All levels people suggest is fanfic you idiot. Admiral level, yonkou level etc. are not mentioned in the manga.
But there is obviously as class for warlord level because they are the famous pirates that are set above the rest. They are part of the three power balance along with the marines and yonkous, so you'd be stupid to discredit them otherwise.
1. Well no shit he would lose to BB
2. Buggy is warlord because of his sovereignty. The people he has in his crew are a threat just like a warlord.
3. Jinbei said Moriah got weaker over the years, and doflamingo didn't do anything to Moriah. It was the army of Px that did.
And even then Doflamingo was unable to kill Moriah.
4. And Kuzan didn't give a **** about Doflamingo hence why he got his ass kicked. So don't be that retard that thinks he can.
5. Mihawk is above warlord level. So was BB before he fought Ace. He was the only one who permanently damaged Shanks, something Hawk eyes could not do.
6. That's the anime, filler boy. And I already addressed Hawk eyes level.
Will you stfu? There is an obvious difference between a 1st commander and all the rest. The 1st commander of a yonkous ship is the freakin first mate, they are automatically the second strongest after Captain of the yonkou ship. So Dogtooth, Marco, and Jack (i think) are all around the same level. Even Dogtooth and Jack have around the same bounties.
As for the filling in the 2nd division thing only applied to Whitebeard's ship not every other yonkous ship have that rule. And even then you need to be strong enough to fill that set, even Shanks said that Ace was strong enough to fill the 2nd commander on a yonkou's ship when he was talking to Whitebeard.
Now does that mean he was the second strongest overall? No! He was just strong enough to fill that vacant spot.
That's the level of where Warlords are suppose to be. That's why when BB beat the likes of Ace, he was given the title of Warlord.