Monkey D. Luffy.
• Luffy's too early to be considered one of the top ten. He's shown great mastery over all three haki's and his second gear as well as third gear has improve to the point where it won't affect his health nor life-span due to him pumping blood in only one particular part of his body instead of his whole body before the time-skip but I still don't see him defeating any of them yet. Let's not forget the only reason he managed to defeat Garp was becaue Garp let him land a punch on him, Garp could have easily avoided the punch.
Magellan.
• Magellan has a unique and powerful Paramecia class Devil Fruit that can easily equal some of Logia's fruit but I can see all the top ten character defeating him. I believe even Luffy can defeat him after the time-skip due to the fact that poison has no affect on him anymore ever since his body's immune system has been boosts to counter any poisons, especially Doku Doku No Mi's poisons.
Jozu.
• Jozu is nowhere near the level of any of the top ten. He's able to give Kuzan a great fight and the only reason Kuzan defeat him was because his attention was toward Marco when Borsalino struck him with one of the attack's from his Pika Pika No Mi and I believe he could be in the top ten but ever since his arm was cut off [If I remember correctly] then it would easily have weakened him in some way. Whilst Kuzan trained to become stronger during the time-skip [Obviously], it's possible for Jozu to trained himself in fighting with only one armed but that would still make him less powerful than he was. Put in note that he is not Shanks where's he's capable of swordsmanship but instead fight using both of his arm. It's sad because he could have become one of the most powerful characters of the series.
Roronoa Zoro.
• Without a doubt, one of the strongest character in One Piece after the time-skip but it seems that no-one has been able to give him a good fight where we could see him at his full power so it's too early to make any assumption that he's capable of defeating any of the top-ten.
Trafalgar Law.
• Trafalgar Law is also one of the strongest character in One Piece but if he were to meet someone who could counter his ability such as anyone with amazing speed and any Logia's then he could easily be defeated since Logia won't be harmed by his Ope Ope No Mi even though he has haki since there hasn't been shown whether it's possible for someone of Paramecia's class to haki-coat their Devil Fruit abilities related to such abilities such as Ope Ope No Mi and Scrathmen Apoo's unnamed Devil Fruit ability where he's capable of cutting through his enemies through music.
Smoker.
Let's examine Smoker's ability first.
• Moku Moku No Mi which enable him to manipulate, create and transform into smokes. Currently, I don't see much threat coming from this Devil Fruit.
Moku Moku No Mi's main/seen attack's.
• White Out in which Smoker shoots normal smoke from his arms and uses them to devour his opponent, then makes the smoke compact to trap them inside it.
• White Blow in which Smoker shoots thick smokes from his arms to blast his opponent hard.
• White Snake in which Smoker launches a long snake of thick snow to make them track/follow his opponents until it grabs them.
• White Spark in which Smoker transform his some of his body or his whole body into smokes and charges towards his opponents.
• White Vine in which Smoker transform into a spiraling of smokes to trap his enemies.
• White Launcher in which Smoker transforms himself into smokes and launches himself towards his opponents.
Conclusion : Moku Moku No Mi currently shows no threat towards time-skip Luffy nor even any of the top ten characters. Anyone with haki can defeat him and due to him transforming into smoke whenever he uses White Launches, it made it easier for his opponents to land a punch or kick toward him.
Haki.
• Kenbunshoku Haki.
• It's possible for him to have mastered this form of haki but during the fight with Trafalgar Law, he didn't show any sign that he have it but it's still possible for him to have it but I, or maybe most of us or all of us haven't realize it yet or it just hasn't been stated or shown yet since it's been stated that all of the Vice Admirals must at least mastered one form of haki's.
• Busoshoku Haki.
• It's obvious that he's capable of using this type of haki since after the time-skip, it seems that almost all the top pirates capable of matching up with any of the Logia's user and I think I remember once where Luffy said "ouch" when being struck by Smoker and since Luffy is made of rubber then it's possible that it was the effect of Busoshoku.
Rokushiki.
• It's been told that every top ranking marines has access to Rokushiki so it's possible for him to mastered some forms of it before or after the time-skip. Currently, it hasn't been shown whether he mastered it or not in his fight against Vergo [put in note that he purposely chose to fight using his Moku Moku No Mi in order to steal Law's heart from Vergo] and Trafalgar Law.
Now that I've explained his abilities, I can say that he isn't capable of defeating any of the top ten yet but I'm sure somewhere in the future, he will definitely become one of the top ten.
Vista.
• Vista is a great swordsmen, it's been shown that he's capable equally fighting Dracule Mihawk but the fight was cut short by the incident where Squard stabbed Whitebeard therefore assumption on him being an equal to Dracule Mihawk should be analyze or shouldn't exist unless it was a fight where there are no incidents to have any sort of effects towards the fight.
Yonkō's first mate which I assume is Ben Beckman[?]
• It wouldn't be fair to assume his strength's based on Borsalino's reaction toward him when he pointed flintlock rifle which I assume he uses a haki-coated bullets or the fight between him and Higuma's mountain bandit's crew since it's been shown that Borsalino continued with his attacks on Heart Pirates submarine and Higuma's mountain bandit's crew weren't much of an opponent for him. Unless his true abilities are shown, we shouldn't hype him too much but I do believe that he is a powerful person, capable of being equal to any of the three admirals before the time-skip.
Sanji.
• Honestly, I don't see him defeating any of the top ten, not in his current strength. He will in the future but not just yet. I'm sure he's improve a lot and it wouldn't be fair to assume his current strength based on his fight against Vergo where he managed to defeat Vergo but only because Vergo shown no interest in fighting Sanji and it seems that his kicks doesn't seem to harm or injure Vergo that much.
Any of the Vice-Admirals.
• I don't see much of them yet except from Momonga, Strawberry Dalmatian, Vergo and Smoker. Correct me if there are other Vice-Admirals that has been shown fighting any opponents, excluding John Giant where he got his ass handed to him by Whitebeard and Tsuru due to her being the strategist of the marines. Based on Oda's logic and plot, he would usually use any of the Vice-Admirals or characters that he categorize as weak during the series and hide powerful characters for the future of the series such as choosing the next to Admirals to replace both Kuzan and Sakazuki.
Other shown Vice-Admirals
• Comil is shown both during Portgas D. Ace's mini story and in the Battle Of Marineford. He's one of my favorite Vice-Admirals due to him believing in "Moral Justice" but his strength hasn't been shown at all. It's obvious that he's capable of using some form of haki and seems to be a capable swordsman but that's his only abilities that we've known so far so it's hard to make any assumptions or theories.
• Oniguma and Doberman both seem to be a believer of "Absolute Justice" which made both of them one of the prime candidates on known Vice-Admirals to become an Admiral but their strength is also currently unknown.
Giant Squad Vice-Admirals
• Both Lacroix and Ronse's abilities aren't shown much. Other giant Vice-Admirals are shown to help Lacroix get on his feet implying that he got his ass handed to him or simply tired from the battles whilst Ronse got his ass handed to him by Whitebeard's Vista and Whitebeard himself.
Vice-Admirals toy'd by Donquixote Doflamingo.
• Mozambia and Stainless abilities are unknown but they are easily trapped by Doflamingo's possible puppet-like Devil Fruit whilst Cancer, another Vice-Admiral who abilities are unknown, couldn't even do anything to stop them from trying to kill each other.
Other shown Vice-Admirals.
• Bastille abilities are unknown and he doesn't seem to be fighting nor received much screen-time during the war.
Filler Vice-Admirals.
• Jonathan seem to be a future candidate for Admirals position even though he's a filler character and based on Oda's way to creation his stories, it's possible for Jonathan to be in the future of the show since Oda wouldn't create a character and put more canon details in them which in his case, being a Sakazuki's protege. The same goes with a character that goes by the name of Bogart [Bogart possibly isn't his real name but added/created by fan in order identify him for future reference] is also a possible Admirals candidate due to him being one of the most mysterious character in the series and since Oda based the three admirals creation based on actors and since Bogart has the similar appearance to Humphrey Bogart, it's possible for him to be the future Admirals, added with mysteries surrounding his creation and appearance as well as his strength therefore it's possible for him to be a Vice-Admiral but currently, it's just a theory.
Boa Hancock.
• It's obvious that she's one of the powerful character as well as the most powerful female pirate of the series shown so far excluding Big Mam due to her abilities being unknown but it's highly unlikely for other characters in the top ten to fall for her Mero Mero No Mi's ability. It's also been shown that her physical attacks are capable of turning anything she touches into rocks similar to Greek Mythology's Medusa abilities whereas any person who look at her face will turned to rock. Her abilities are one of the unique and if-used-properly-with-no-plot-related-would-be-one-of-the-strongest Devil Fruit but currently, it's hard to make any theories nor assumptions on her abilities.
Donquixote Doflamingo.
• Considered to be one of the most powerful characters in the entire series based on hype and also because he is the only Shichibukai shown before time-skip that the Strawhats' haven't encounter. He's capable of slicing through anything by using his finger whilst controlling others like puppet using his fingers as if there's a string attached to the person he's using it on. His Devil Fruit is not only unnamed by also confusing and there has been many theories on whether those are even Devil Fruit or an advance version of Haoshoku Haki but like I said before, unless a character strength is known, it's better to not make any assumption because based on hype alone, he could easily be top five or even top two.
You've shown a couple of great characters possible to be in the top ten but most of them strengths are either unknown or their full capabilities are not fully shown. I'm sorry if there are any typos because I'm getting sleepy and correct me if I made a mistake on my explanation.