That being said, does it need to be fixed?
That change was in SBP. If it went unnoticed for this long, isn't that pretty strong evidence that the Command Tank's probably fine at 20%?
Imo the problem was commander design and not with PzIV. Mobile defense aloud both AT (Puma) and AI (C.PzIV) to be called with no tech. Puma and PzIv should not be in the same commander it is a bad design.
Having that said there are issues with C. PzIV and with command vehicles auras:
1) C. PzIV did not receive any of the buff the normal PzIV got like reduced price or better scatter for OKW, so it currently has about the same AI capability while far worse AT capabilities while being more expensive.
2) Imo all command aura should scale with veterancy giving Player a motive to risk them
3) Command aura should have part one passive always on and one timed limited (cost in not necessary imo)
My suggestion would be to change the gun of PzIV with that of Stug-E (its the same weapon) and to add to both of them a direct fire mode with low penetration but some deflection damage.