The fact that Churchill is not limited to one makes it even more OP.
Well, that's your opinion you're fully entitled to, not a metric supported fact.
If you losing a Churchill to a single RF, a Pak or Stug is rather hard to achieve.
Hence, plural in the very sentence you've quoted right there.
For someone who literally balances the game based on semantics, I expected you can the difference between singular and plural in english.
Slow speed means little when it hardly provides opponent with an advantage. The unit has very fast rotation, acceleration, stock smoke, a tone of HP and high rear armor reducing the effect of the slow speed.
And then, you faust it once it reaches threshold and it literally turns into an emplacement.
The role of the KV-1 and Churchill is that of a break thru tank, it's role is not that of a hard counter to medium tanks. There are other units for that role available to the faction.
It is, therefore they have very high durability and very low potential to actually deal any damage that regular med wouldn't do.
Also, that breakthrough role means they can run towards and past ATGs and cause some chaos, yet literally no one does that.
See, this is what Sander said starts to apply - role is one thing, stats is the other, just because stats allow you to use it in certain way, doesn't mean you should or you will.
Because flanking should be rewarded in similar manner it is rewarded for other heavy tanks being flanked by mediums.
Other heavy tanks have TREMENDOUS frontal armor and main gun that no med can stand up against.
Last time I've checked, Churchills and KV-1s weren't deflecting up to 60% of ATG shots at max range nor were they penning all medium vehicles with 100% chance.