This. Buffing the AI capabilities of T37/76 makes T70 useless. And it makes T3 even more I would still suggest penetration buff at vet3.
Then why not moving T-70 to T4 and SU-76 to T3?
Why I should spend 70 fuel for an anti-inf tank when I can make T-34 for 100 fuel which is decent in anti-inf and can fight vs tanks or why I should spend 70 fuel for SU-76 when I can have SU-85 or Katy for the barrage?
T-70 would be nice to support SU-85 and defend it against shrecks and SU-76 could support T-34 from range against Pz IV.