Kv1's purpose is to counter medium tank's because of it's armor but be countered heavier tanks like panther and so on. At least that's what the sweetspot for the kv1 should be.
Maybe the churchill is a bit too good, just saying
Both Churchill and KV1 don't really have a place in the game. Churchill might counter P4 in like 8-10 shots, because the front armor of Axis tanks is too tough for KV1/Churchill to penetrate reliably.
Churchill and KV1 are just the heavy version of Panzer IV without the mobility or the same anti-infantry firepower. Their weapons are only reliable against light and rear armor, so not really useful due to their movement speed.
Paks, stugs, panzerjagers and raketens just farm veterancy on these tanks, the HP pool of churchill makes it slow to repair, where Soviets are slow at repairing large HP pools by default. Veterancy bonuses of these tanks don't give them extra range, damage or pen, just the reload speed. So your heavy full vet tanks are still going to be useless against panthers and heavy axis tanks due to the low penetration. Even Brumbar with veterancy gets the armor bonuses to the point where you are better off shooting shells at infantry with your Churchill.
Plus your slow and short range (40) tanks will get fausted all the time making them even less useful in engages. Churchill has the vet 3 ability to repair the slow itself, but it is only useful if you run over a mine because the time to repair is 15 seconds.