All this is done in SKR pushing those guys to the max and then giving them SKR reiatsu as a boost. Imagine how Kenpachi will come out, and all he had to do was wake up, no training, no super reiatsu, nothing. Just wake up his true self and he is already a threat to BB. If he went to SKR he would destroy the universe, probably already on par with Ichigo, anymore and he could win everything himself