You want command tanks to affect player only units? But SU medics heal any allied troops nearby. UK forward post and US ambulance can reinforce any squad regardless whom player is it.
Not really understanding this logic here. There's a massive difference between giving a recieved damage modifier to your teammates during combat, than healing them out of it. And i am only talking about Osts command tank being limited to the controlling player, because of the type of aura.
The Opel Cargo trucks used to help your teammates. Then Relic realized that was INSANELY overpowered, so they limited it to just the controlling player. So you can't just say "teamplay" is the reason to keep them.
And I'm not forgetting anything about game types btw. Osts command tank saw plenty of use in GCS2, which was a 1v1 tournament. Clearly the unit can still be useful without it buffing 2 or more players worth of units.