yea, my thought was to replace tac movment as i got messed up with my suggestion and the OP so i already had tac movement as a write off, but you are right
i know the unit was originally a defensive unit, but i think a defensive command unit is a fine line between being too much and not worth the effort, even now poeple think ~only~ tanking 1 extra hit for all armour isnt that good of a buff without needing to do anything. so an active defensive ability would be a tough duck i think, finding the right balance would be quite tough. additionally restricting it to defensive (although i do like your suggestion for defensive posture) stagnates somewhat. but thats just a personal opinion of course
to take a bit of the pressure off that aspect id like the unit to be worth it even without the support options- something hitting like a stug E with a turret might be enough to be attractive (it IS limited to 1 at a time) and then the support abilities wouldnt need to be as hard to strike a balance on know what i mean?
Yeah just making the main gun better in some way would definitely be a good idea. And the support role could also be designed to improve with vet, like it does for some of the other command tanks. I've seen Vipper suggest this numerous times I think, but might of been talking about a different unit
I think one or two of the support abilities themselves should be somewhat stagnant anway tbh, but if the main gun is improved, and it gets things like smoke shells and strafing runs, that still gives it some offensive punch as well. But at the end of the day, if you want a medium that can contend with tanks, get a regular p4. If you want medium that focuses on infantry get an ostwind
The commissar has offensive and defensive abilities, I think the command p4 being an upscaled late-game commissar would be ideal