Okay so I decided to take the original list I posted, edit it slightly, and throw in every One Piece character who has ever held the title of Warlord(just to make it more interesting). The only Warlord I won’t include is the current unknown 7th Warlord, because well, we have never seen him. My list is also only based on the Pirates themselves, not their crews.
1. Blackbeard: Is now a Yonko
Has 2 devil fruits, 1 of them is the most powerful Paramecia class fruit in the world
Defeated firefist ace with one of his devil fruits
Held his own against Whitebeard with 1 devil fruit(kind of)
Fights Sengoku equally(Though I'm not sure he does this in the manga, I think it's anime only)
2. Mihawk:
Former rival of a Yonko
Strongest swordsman in the world
3. Doflamingo:
Is able to manipulate(at least) 2 vice admirals at once (does this at the Shichibukai meeting)
Stopped Diamond Jozu in his tracks with no apparent difficulty
Is implied that if he weren't a shichibukai, the admirals would be sent after him
Is able to take down a Vice Admiral with almost no effort
Conqueror's Haki
Effortlessly defeats Moria (though he probably just sat back and watched the Pacifistas do this)
4. Kuma:
Wreaked havoc on Thriller Bark in one attack
Stopped Oars Jr. dead in his tracks
Can move at insanely fast speeds
Can block any attack
Can shoot lasers
5. Crocodile: Fairly underrated for a Warlord
He technically defeated Luffy 3 times before Luffy defeated him (Stabbed him the first time, dehydrated him the second time, poisoned him the third time)
Can drain the water from anything
Has extensive knowledge and skill with his logia class fruit
Takes a shoulder blow from Diamond Jozu and continues fighting
His attacks can be devastating
Fought Whitebeard in the past
Kept in Level 6 of Impel Down
6. Jinbe: High bounty after the timeskip
Kept on level 6 of Impel Down
Immobilizes Moria with one hit
Black Belt in fishman Karate
Blocks an attack from Admiral Akainu
Is able to stop Gear 2 Luffy without much effort(pre-timeskip)
7. Law:
Supernova with a very high bounty
It is implied (sort of) that he held his own against Fujitora and Doflamingo at the same time
Is able to hold his own against Vice Admirals
Somewhat able to hold his own against Doflamingo
8. Hancock:
Can turn people (and things) to stone
Very strong at hand to hand combat
Can immobilize several people at once with her beauty
9. Moria: Can empower himself with his shadows
Relies mostly on his Zombies to fight for him
Uses his devil fruit to keep Luffy at bay while he relaxes
**10.**Buggy:
Actually have a small fight with Mihawk during the Whitebeard war, and does fairly well for his strength level
Can fly (under most circumstances)
So here it is, I don't think I missed anyone, but let me know what you guys think!