No.
Saying yes is accepting that they are more cost efficient and all-round than other units.
To my mind, saying "yes" is accepting that they are currently more cost efficient and increasing their cost to better align it with their performance.
The current situation is:
Your first T34/76 costs you 120+100=220 fuel.
Your first IS2 costs you 230 fuel.
Your first SU85 costs you 120+120= 240 fuel.
Your first ISU152 costs you 260 fuel.
German numbers are similar to this. (Just think about a Tiger at 230 fuel vs. a Panther which has a build cost of 175 alone, to say nothing of the teching cost)
Change the costing system to requiring tiers to call in heavy tanks and you change 2 things:
1. Extend the mid-game and end Company of Call-ins (tm)
2. Align the cost of heavies with their performance
P.S. ISU and Elephant still need nerfbat application to the face.