Axis can do the same at the moment, ost can provide ht and use gren blobs or support volks blobs. Does it happen? Not really. You still need fuel to build m5 so it would take time before they can field it. Currently penal spam supported by m5 can be executed too but nobody does it because you penals reinforcement speed is comparable to that of ost grens. So its kinda slow. Im not saying it wouldnt happen but it wouldnt be that effective. Cons supported with m5 might work because they reinforce faster and their reinforcement is cheaper, support weapons supported by m5 would be more probable too. It would actually make use of soviet clear advanatage which is cheap and fast reinforcement of shitty units. Because the good units reinforce slow and are expensive to do so.
I dont think it is "balanced" in the sense of how soon the halftrack can hit the field.
Ost halftrack
- Battle phase 1 for 100 mp, 40 fuel
- T2 building for 200 mp, 20 fuel
- Half track for 250 mp, 30 fuel
Sov track under your suggestion
- T2 building 160 mp, 20 fuel
- Halftrack 270 mp, 30 fuel
I don't think a halftrack this early is going to be too balanced, even without meat chopper device.