Vet gain is only based off of the health of a tank while durability is a function of both armor and health. Therefor if the goal is to reduce vet feed while maintaining durability you need to to reduce the health pool of the tank while simultaneously increasing its ability to mitigate damage. Using your methodology we can lower the HP of the Churchill and increase its armor to achieve roughly the same durability level. For example:
Churchill, 240 armour, 1400 HP (durability level = 336K)
Speculative Churchill, 325 armour, 1040 HP (durability level = 338K)
The speculative Churchill in this scenario has roughly the same durability as the current tank but more of that durability is based around armor deflecting shots than health tanking hits. As a result the speculative Churchill will produce less vet for opponents at the cost of being more prone to RNG elements (it can survive 2 fewer penetrations than the current Churchill) and a bit more vulnerable to superheavy AT (JT, Elephant, Pak43 all require one fewer shots to kill).
Below are the average number of shots require to kill each Churchill variant:
vehicle health/(opposing weapon damage*(average opposing weapon penetration/armor))=average # of shots to kill
Churchill
vs P4 1400/(160*(110/240))=19.09 shots
vs Pak40 1400/(160*(190/240))=11.05 shots
vs Panther 1400/(160*(240/240))=8.75 shots
vs JagdTiger 1400/(320*(240/240))=4.37 shots
Speculative Churchill
vs P4 1040/(160*(110/325))=19.20 shots
vs Pak40 1040/(160*(190/325))=11.11 shots
vs Panther 1040/(160*(240/325))=8.80 shots
vs JagdTiger 1040/(320*(325/325))=3.25 shots
As you can see 1040 HP and 325 Armor would achieve similar survivability vs most sources of AT while bleeding less vet. Although this speculative Churchill would be more vulnerable to bad sequences of RNG if the smoke was fixed it could effectively mitigate those times with a well-timed smoke cover. I would favor this approach over the alternative because it works within the existing ruleset instead of creating special vet gain modifiers for one specific tank.
This of course assumes we want the durability to remain the same. If we wanted to make the Churchill more durable we could always increase the armor further (1040 HP 375 armor would put it at the same durability as an IS2).
Kind of off topic but what do you all think of letting the major place a forward retreat point like a pathfinder places a reinforcement beacon so that the major can actually be used on the front line for his abilities? Major arty is pretty bad but even if it was improved I doubt you'd see majors being used for it on any map larger than a 1v1 since the forward retreat is too strong.
I think one of the main issues with the churchill is that it has very little impact when it arrives. The main gun is hardly special and the low armor means that all the AT your opponent currently has will penetrate it easily. Since it doesn't create any matchup mismatches your opponent doesn't have to adapt their strat to cope with the presence of a churchill. By contrast when the comet arrives it outclasses medium tanks/AT infantry and is a constant flanking threat. This in turn requires your opponent to react to the comet by placing tellers or investing in panthers/dedicated TDs. For the curchill to be successful it needs to be able to create a similar kind of mismatch when it arrives on the field.
Why the limit on Heavy Tanks then? I mean, if what you say is true, I don't see a point in the heavy tank limit being 1. Yeah sure it's not the same type of unit but still, it's a limit, something which you're opposed to.
Heavy tanks are generalist units with no major weaknesses that are capable of combating everything on the field hence why the tanks are limited to 1. Even a long range tank destroyer will struggle to deal with a heavy alone. Before the limit was imposed the safest strategy was often to just try to produce more heavies than your opponent. This is not the case for arty which has a very clear weaknesses to offmap strikes (for static arty at least) and zero field presence. Producing too much arty will leave your army at a very significant MP or fuel disadvantage that a competent opponent can exploit to destroy said arty.
and remove the speed penalty on the smoke ability.
+1.
The reduced vet solution isn't a bad idea but it would mean creating specialized game rules for one specific unit that aren't in any way clear to the average player. I'd much rather see the churchill just brought in line with the survivability of every other heavy tank.
Something to keep in mind about the old T34/76 with the 5.6s reload is that it was also produced from T3 and arrived earlier than the current T34/76. What made that tank good was not just the RoF but also the timing window it enjoyed before it was outclassed. With the current T34 stuck in T4 and arriving later it needs measurably more performance to succeed in it's role as a medium tank. The current performance is akin to producing a 222 to harass when the enemy already has a Stuart.
The pricing on the 222 is pretty generous atm and might need to be adjusted upward a bit. Alternatively the auto-cannon could be made a muni upgrade again. That way the 222 would function similar to a m20 when first built but could then be upgraded for improved AT.