See, that's why I don't discuss power levels anymore. People interpret very similar situations differently, when it comes to Admirals, then when it comes to Pirates.
You are assuming that Kizaru and Aokiji, one relaxed to the point of being high, and the other lazy as all hell, actually went all out on the commanders. Hell, you are assuming they actually went and started fighting seriously.
You. Are. Assuming. That. Kizaru. Started. Fighting. Seriously. Think about it for a second.
And then you specificly say that the same circumstances, Akainu not losing during his off-screen fight with all of the remaining commanders, are different because commanders were not fighting seriously. Even though nothing in their stance nor characters suggest that. If Marco by himself can fight evenly with Admiral, as you say he can, than taking him, Crocodile, Vista and all of the others head on, and coming out of it without any significante injuries should count for something, don't you think?
Also, if the momentary distraction is all there is to losing the battle, then Blackbeard would be one of the weakest characters in all of One Piece.
As for your argument about ten days fight between Aokiji and Akainu, I would like to point out that they are both Admirals, and I'm arguing that admirals are stronger than Commanders.
If anything, that fight should tell you just how much they are holding back all of the time.
this may cause a war but i also think whitebeard was the weakest yonko with his health gone bad i just cant see shanks loosing to him:ninja:
that would make the other yonko admiral level