Well the thing is Smoker has been introduced as Vergo's subordinate, so even in the marine, Vergo's position was supposed to be greater, something backed-up by Vergo's superiority in itself featwise, defeating Smoker with moderate difficulty and Smoker himself telling to Tashigi in advance that he may die in his confrontation with Vergo. Everything in Punk Hazard was going around the fact Vergo was above his level.
Vergo was above Smoker no doubt personally I think it was more of a high diff fight Sanji vs Vergo was mid diff but I think you're looking at ranks as to much of a gauge for strength. Vergo was above Smoker, Law and Sanji physically and funnily enough both Sanji and Smoker are physical fighters Vergo was also shown to be superior to Law in aspects as well Law was fortunate Vergo was overconfident that's all.
Same Vergo who Sanji contended to in a small skirmich similarly i'd say and that without prior knowledge on the opponent(unlike Smoker). Add into that the fact Sanji performed much better against Doflamingo than Smoker and i think the reason of my doubts in current Smoker's superiority over Sanji isn't far-fetched.
There's nothing to suggest Smoker had prior knowledge to Vergo's abilities there's no proof for you to back that up at all not to mention Smoker's objective wasn't to win and doing so but himself at an advantage from the get go. Vergo used Haki and his signature weapon to put down Smoker who wasn't fighting to win while Vergo easily overpowered Sanji without Haki and without his bamboo stick.
In regards to Doflamingo it isn't really a fair situation...Smoker who was without his main weapon and also was injured from the Haki hits he took from Vergo hits that cracked Sanji's bones not to mention Doflamingo was angry and serious against Smoker he wasn't playing around like he did with Sanji.
Not to mention someone stronger than Sanji like Zoro showing superiority over someone with a similar rank with Vergo or Luffy himself who is about to beat Vergo's boss. Maybe Smoker will come down much stronger later in the story, but currently i just think he isn't there yet. You say i'm underrating Smoker when in fact i'm just presenting reality
Again rank doesn't mean everything feats and portrayal suggest Vergo was far greater than current Pica who without his huge golem hasn't shown anything impressive. Vergo was beat by Law who is stronger than Zoro so portrayal wise wouldn't that prove Vergo's superiority by your logic? Also there's no proof Luffy is going to beat Doflamingo on his own so far Law has had to help him land a hit on Doflamingo.
Reality is Smoker is Luffy's rival not Zoro's not Sanji's but Luffy's story wise and character wise it makes more sense for Smoker to be on a similar level to Luffy otherwise what has Oda been building up for the last 10 years. So what it really comes down to is you either believe that Oda has been wasting the last 10 years building the rivalry between Smoker and Luffy and has thrown it away to the point Luffy can mid diff Smoker. Or you believe Smoker may not be as strong as Luffy but is on a similar level to push Luffy to a high/extreme diff fight and continuing the rivalry the two have with one another.
Story consistency and character development is where we differ I don't believe Oda would throw away something he has spent so long building and people's personal belief or opinions on characters isn't going to change my mind.
