In a team game if you've got multiple people trying to counter one player's churchills, you're losing elsewhere, you need to be able to kill them yourself somewhat reliably. a 3v3 us essentially 3 1v1s.
Its a lot of fuel/pop cap to have 3 churchills on a single brit player. I doubt youll face double/triple brits in most games and if they can bring 3 churchills out then you should have panthers/tds/atguns that can beat them back.
The Churchill is definitely a good unit that gets propped up since the Comet is god awful and it is very powerful if you manage to get it out when axis players dont have proper counters. But those counters arent particular difficult to get before the churchill comes out.