Kenpachi , Byakuya ,Toshiro , Shunsui and Ukitake vs Shikai Yamamoto
FKT versions for the 5 Captains. Restrictions: Only Shikai games that were shown in FKT ....no Bankai allowed for Yamamoto , Shunsui and Ukitake. Location: Marocco Starting distance: 19 meters Stipulations: Kenpachi cooperate with his teammates , he does not tell them to ''stay out of my way...

The Captains win comfortably.

They were managing to stay alive, but they were also the only ones taking damage.Shunsui + Ukitake alone were giving him a fight in canon.
I wouldn't exactly call that giving someone a fight even if a lot of people don't give them enough credit for it.
No he's not.FKT Kenpachi should be around their level as well,
Kenpachi AND Byakuya beat Yammy and they were both beaten and battered by the end of it. Bare-handed Yamamoto blitzed and two-shotted Wonderweiss like he was fucking nothing who is on par with Yammy and Stark by feats.since he beat Ressurecion Yammy who is > Starkk.
No he wont.Yamamoto will get overwhelmed eventually.
If Kenpachi isn't dying in the crossfire, the guy who is outright portrayed as a peer of his at this point (Byakuya) isn't dying in the crossover either.Byakuya and Toshiro die in the crossfire.
Of course the reality is they are ALL dying 'cause none of them can do shit to Yamamoto.
More like they aren't relevant here nor is anyone else.But they aren’t needed here.
The Seniors last the longest but are still dying eventually.