Heavy tanks should be a late game jewel for your army, not a rushed unit.
Then we'd keep the problem that heavy tanks are generally not very useful because they come out so late they have to go up against vetted ATGs and TDs and rarely achieve anything.
I personally think a Heavy Tank rush should be a strategic option, just like how for example Ostheer can choose to skip T1 and rush light vehicles. Imo it should be balanced by risk and reward and opportunity, probably with a build time to help smooth out the shock timing, but not by an artificial checklist.
Rushing a Tiger or Tiger Ace right now is not an automatic win as long as the enemy suspected it and got a TD, as even a single TD can greatly mitigate the heavy's impact for almost half the price. A rushed Tiger/Ace will not have a lot of support and going up against a pre-built TD has a good chance of backfiring. But it does punish those who are either completely behind or ignored all the signals and got medium tanks or AI tanks or went for a lot of light vehicles. It would give heavies a strategic role (besides their tactical role of damage sponging and spearheading) that they currently somewhat lack.
So TLDR personally I do not like the idea of a dual requirement because it feels too artificial to me. But if it proves to be the only solution and if it's what everyone wants...