I consider Ace & Yami Teach as stronger than Marco/Jozu/Vista trio, so no, I don't cap Ace's Powerlevel with some fanmade YC1/2/3 levels.
Eh..
I think that Ace was equal to Marco
He had more potential due to being a Conqueror as well as being Roger's son (it's even implied he'd have eventually became a high top tier or a god tier if he weren't executed immediately), but at the time he wasn't above the top Commanders imo
But he also wasn't below them. So yknow
Anyway this is more of an argument about DC/AOE than AP, if we're talking about AP then there's several cases of a Commander having better AP than a Warlord. Jozu managing to bust Kuzan's lip and also making Crocodile bleed a lot (as well as Croc complimenting his speed and weight), for example.
Cracker cutting through G4, which Doffy couldn't do, for another example.
King's... Entire existence.