Round 1:
Without Vsbattle logic: Kenpachi should high diff. Team has the advantage that they outnumber Kenpachi + at least Kizaru should be faster. However, Bleach characters are known for her speed as well. You also don´t need to deactivate Intang, since Bleach characters can affect/damage souls directly with Zanpakutō. That alone should bypass the element and attack the true body.
With VsBattle logic: MFTL+ Kenpachi blitzes all 3 before they can react in under 0,0000000001 second. No explanation needed lmao.
Round 2:
Even with equalized speed, Kenpachi isn´t weak. I would even claim that Kenpachi should have comparable or even far better physics. His high pain tolerance allowed him still to fight with several damage. There is still the posssibility, that they can overcome him with AoE, so i would say it can go either way.