The idea is to remove some of the frustrating elements of paying for a td/high armour unit and it not doing what you are paying for.
Medium AT has a good balance for how well it works, same with ligh at (as limited as it is) but once you amp up the scale things start to fall apart. You pay ~200 fuel for a tank that won't bounce anything is just as frustrating as buying a ~140 fuel hard counter that doesn't pan anything.
I'm looking for a reliability and predictability to the most unreliable and unpredictable portion of the game. It would still have RNG, but also still be predictable.
In fact, i think there is more good option - increase health pool of heavy tanks or damage reduction (like kv-1 have). If TD get decreased pen with deflection, it become very unreliable against heavies (buy 130 fuel TD without turret, potent against only mediums...not good choice). You couldn't rely on TD that have low chance to penetrate and instead deal small damage. How you supposed counter Panther with blietzkrieg? Only if, you don't want make from panther slow-moving unit, to compensate decreased penetration of TD. Problem that Axis have heavy armored rush units. That could easile outmaneuver your TD, easpecially on open maps.
IMHO, i prefer health-pool, because damage reduction only good for such units as kv-1 (low penetration and low mobility). Yea, in such case you need spend more time to repair, but i think it's better repair your tank neither build new one?