I don't think Sander needs explaining how different weapon types work, mate... And by saying that Hetzer and KV8 got different treatments, you imply that the factions they are in have similar units. That's just wrong.
Well if one argues about overlap between a flame tank and main battle, I have to poin out the diffidences.
Actually I was the one that pointed that OKW and Soviet do not have similar units...
Your proposal would not change anything on map dependency.
Not it would not but it would make KV-8 less of investment, so less of risk and thus a better choice on certain map.
Downscaling cost and performance just clutters Soviets comparatively light tanks.
I do not see how KV-8 overlap with soviet light tanks but even if it would I do not think it would a bad thing especially after reading again and again, how much soviet are depended on the T-70.
On the other hand KV-8 was fine for a long time before it was patched and there is little indication that the proposed changed would cause problems. On the contrary one might actually have more reason to built SU-76 and support his KV-8s
At the moment it is a beefy AI specialist, something that Soviets lack in their stock rooster. Just like Soviets lack anything beefy in their stock rooster, that's why literally all their doctrinal tanks (maybe with the exception of the lend lease Sherman) are heavier than anything they could usually field.
And if we accept that if it become cheaper it will overlap with t-34/76 we have to accept that now it overlaps with KV-1.
The Hetzer just collides somewhat with the Luchs, a unit that OKW does not even have if they go for T1. OKW already has a beefy tank unit with okay AI (the P4 as you said), so why move the Hetzer into the same spot?
Of course the unit can still work like that, but giving them a distinct role is just the straight up better option.
My suggestion for hezter (and other specialized units) is to become call-in and thus increase built diversity.