The churchill and KV-1 won't be worth using at range suddenly just by giving them more RNG dependant health pools, nor will making the Church a random gamble on it dying before it even gets close enough to throw a grenade.
I suggestion was lower the health by two AT gun shots so it's the same as the majority of heavy tanks, including the KV-1.
In return, it gets the KV-1's +25% repair speed (so it's on the field
more rather than spending most of its time eating up your entire repair capacity) and frontal smoke shells. That gives it the ability to blind AT guns and HMGs.
It's still a Tiger's worth of hit points and armour for 165 FU, but now it can do more than eat shells.
I personally think that's a net improvement.
I wonder if churchills could be buffed with a self critical repair skill to figth that crawlspeed could be possible.
They've got a veterancy ability where they repair their own engines.