Honestly Marco is pretty overrated. The only fight he's seen through is when Marshall shut his lights out. Right now he's using his intangibility and evasiveness with little real offense to boot.
Jack < Kaido... that's not really a point. Saying he's less durable or has less stamina says nothing about Jack because Kaido is considered the toughest one on one fight in the world. Being under Kaido can still mean Jack is so tough that they might as well be the same to a large majority. Jack is really, really high up there, and Kaido himself says as much.
If you're saying that losing to two admirals takes away from that though, I think this is lost on you as we haven't seen anyone withstand two admirals. And like I said to someone else, it's probably not gonna be something you get if you think Ace vs Jinbe is the same as Jack's raid on Zou