Well, a T-72 costs 45 somethings. Fully vetted the accuracy is almost as if it had 9 instead of 3. The cost of fully vetted should be 90 somethings. This is the same cost as the basic T-80 model. There are still differences, of course, but maybe a high vet T-72 can in fact substitute for a T-80?
The T-80 is a Big tank which is easier to hit, i.e. attacking units get +1 on their accuracy when shooting at it, according to The Big Chart. The T-72 is Medium, there is no accuracy boost for the enemy.
T-80 has Rof 10 AP 9, end of argument.Regarding the Op's question:
I think you need one good line of heavy tanks like Leop 2 or T-80's with all variants unlocked. After that it depends on your playstyle. Usually you should have more than enough heavy tanks with a 2-3 variant line.
Abrams line is Ok but not great. You cannot face the best tanks head on without serious support and Leopards are even faster for flanking purposes. The base Abrahms is a good medium tank hunter though.
Challengers are slow and have no variants, severely limiting your combat flexibility as the only heavy in your deck. They are good for supporting though. Call them in later on frontline call in sectors.
Leaves you With Leopards pretty much, even if they weren't that good. Same goes for T-80's. No other Pact tankline has the ability to compete head on with Nato heavy tanks and no other heavies are really needed.
_________________Formerly shugyosha on these forums and still shugyosha ingame
Patch the players instead.