Why is this being used to disregard/downplay the feat? The very fact that Akainu 'let his guard down', if that is even what happened, doesn't detract from Whitebeard it detracts from Akainu. If his guard was down, that just means Akainu was being stupid in the middle of a war and Whitebeard had the skill to overcome admiral-level Kenbunshoku haki.
I'm not downplaying the feat. My point is that top tiers all have the capabilities to do significant damage to one another when they aren't expecting it so that back and forth is not full confirmation that Yonkou as a whole are superior to Admirals.
CoO is the most inconsistent ability in the series which only works when the plot calls for. Despite it being a thing, distractions and tunnel vision happen all the time in the series. Same thing happened to Marco and Jozu a few chapters before. Even in this current arc, we have confirmed CoO users letting their guard down in clear combat situations and getting injured.
Also, I don't see how you can say Akainu wasn't overwhelmed? After Ace died and Whitebeard got angry, Akainu got taken out of the fight in two hits (the second of which he didn't have 'his guard down'). What would Whitebeard have to do to overwhelm Akainu in your opinion?
When the two were completely focused on one another, neither held the advantage. Akainu even parried WB's bisento with a kick and managed to hold it before having a small back and forth. When WB got sick, Akainu took advantage of that situation. Next time they met, it was WB getting his hits in return. Both only got their licks in when guards were dropped.
If Admiral = Yonko in your eyes, why did the Marines require the Shichibukai? It's stated throughout the series that the reason the balance of power works is the distrust amongst the Yonko; that's why the Marines fear a Yonko alliance so much. Why would they fear a Yonko alliance if the Marines have more Yonko-caliber fighters plus the Shichibukai & Garp/Sengoku? The fact the entire marines and the Shichibukai were assembled for just Whitebeard (who ultimately was killed by Blackbeard's crew not the Marines), and then gave up the fight when Shanks appeared says enough IMO.
Admirals rivaling the Yonkou Captains doesn't mean that the Marines as a whole is capable of going against a Yonkou crew and their numerous allies. Even if the Admirals can take on a Yonkou member comfortably, it's not like they can split up the entire Marine force to go after each individual member themselves.
Their role in the World Power concept makes no real sense, but The Shichibukai added extra manpower and reputation. They didn't help with anything in terms of going against Yonkou. Hell, most of them were allied with Yonkou. Nevermind that none of then even got near WB in Marineford. Bit of a tangent, but it'd make more sense if Shichibukai were Pirates on the front line against certain Yonkou or former crew members.
Two Yonkou meeting means that they have every single asset under a single banner. Crew, weapons, allies, the whole shebang. It's implied the Marines don't have the sheer manpower to match an alliance of that sort. That being said, while the fodder Marines are worried, the Admirals seem rather nonplussed. It's a situation, but they aren't scared. Kizaru was ready to jump up and head to Wano himself to handle things. And Akainu only stopped him, not because of the alliance, but because of the Samurai being an unknown variable.
As I said earlier, while the Admirals may be capable of going toe to toe with Yonkou Captains, there are just way too many allies and crew members in the way to get to that point. They beat WB and it cost them a lot of manpower and Marineford itself was on its last legs.
They didn't "give up". The Admirals probably could fight Shanks and most of his crew. Aokiji and Kizaru were still relatively fresh and I assume Akainu was salivating at the potential opportunity to fight more Pirates. But they stopped fighting because Sengoku agreed with Shanks that any more fighting would just lead to unnecessary casualties, especially after they accomplished what they gathered to do. Had they kept fighting, they would've been at a massive disadvantage in terms of manpower, especially with Hancock chasing Luffy Mihawk just bouncing, and just losing a ton of men.
The Admirals can equal the Yonkou, they just don't have the means to get into a direct 1v1 fight. Oda has recently began to mention them more and more within the same breath, implying Big Mom had the potential to be one and having Luffy state that he plans to take down the Yonkou and Admirals.
