[Jn183]

Originally Posted by Vicious

Spoiler:

I think there is a commander of the 1st Squad, we just don't know him yet.
White Beard as the commander of the 1st Squad doesn't make sense. He's the captain, he rules all Squads, he commands them all. I'd say there are about 3-4 "Squads" from the White Beards, and Ace is the commander of the 2nd one.
Even though, I don't think that the rule "1st Squad has to be stronger than 2nd Squad" works. It may work like the Shinsengumi and the Shinigami in Bleach (the 11th Squad is said to be the strongest of the 13 Squads in the Soul Society; and the 4th Squad is the weakest of them all).

Summing up, Ace might be the strongest man in the White Beards after White Beard himself. He may command the strongest Squad from the White Beards. Or not. We can't really prove this, after all.

Spoiler:

It's a possibility that Black Beard was the 1st commander btu he split