I see three options for this unit:
-250 should come with 0 CP. Buildable in T1 after upgrading battle faze I. Let it become an ostheer version of soviet m3 scout car.
- comes with unique unit inside with some special, interesting abilities
- give them upgrade for MG (which have time ability to suppress) and mortar upgrade. Diversity of upgrades would alow to call more than 1 of this unit and use them diffrently. Which would make this unit more usefull late game if it survive early-mid stage of the game.
Eigher way unit should get cost reduction or HP/armor buff. All of this should also be done with commanders revamp. (Sad wet dream)
