The 251 halftrack, SU85, and SU76 have pretty bad vet abilities too, maybe those could be reworked?
I don't think that tracking is bad if it worked as it did previously. Su76 needs a huge overhaul on the unit itself rather than only the tracking ability.
Regarding the 251 HT, i used a couple of times the ability on the times of FHT/Vet2 KV8. Right now, as how the unit plays, i think a munition cost ability working as the ambulance from USF could work.
251 Halftrack:
Vet1: supply medical kit. For 45muni start healing everyone on X range from the HT. Movement or combat stops the ability.
Here are a couple I thought up:
KV-2: 152mm Barrage- Fires three shells out to 100 range. Can only be activated when deployed in artillery mode. 80 munitions. Short cooldown, so you can make use of the hundreds of munitions Industry tends to float.
KV-8: Flame-wall- Shoots a wall of fire in a 45 degree cone for 10 seconds- think dragon tank flame wall from cnc generals. 60 munitions. KV-8 cannot move for the duration of ability.
KV-1, IS-2: Man the Guns- Rate of fire increased by 30%, movement speed cut in half. 50 munitions, remains active continuously until deactivated, much like Take Aim on the 57mm.
KV2: i guess it can be equal to the Brummbar ability. Bunker busting barrage.
KV8: i think an area denial ability (fire working with DOT on a zone) should work better
KV1/IS2: yeah that kinda makes sense. But again, i don't want an ability which would boost too much the performance of units which are on a fine line (IS2). It's should be pretty fine with the KV1