I'll tell you why Kaido is going to give them an extreme diff fight, because he is the overarching Villain of the post skip saga so far.
For story telling purposes his defeat should come at high cost.
That is all, this isnt about perceived Pls or calcs or anything like you're doing rn,
if we were to go with Logic the SNs shouldve been trashed, but since the plot dictates that they need to be as strong as this to have a fighting chance then plot will also dictacte that Kaido will go down in a phyric victory.