Mobile Unit Call-in

Because units from both armies are called in from off the map, rather than spawning at their buildings, I suppose to simulate reinforcements from a greater army/HQ elsewhere offmap, then what about, perhaps, these units being delivered by an AI truck or halftrack to minimize the time it takes to reach the field?

A basic, flimsy, unarmed truck unit not unlike the Opel, that transports units to the map edge, the HQ, rally point, or even somewhere on the map. Garrisoned or attached units could hop off or detach at any time in their journey where the truck would promptly retreat to base and back off the map.

If the delivery truck did bring units out to a rally point on the map (or just dump them at the edge of any friendly territory), then there would be an actual supply line of units that could be attacked (units in a blowing up transport are sad units) for strategic gains, a danger to offset the speed of the transport. As a one-time benefit for fielding a new unit, there wouldn't be a lasting advantage, and if such a gameplay mechanic were ever to exist, its timing could be balanced via being an HQ/t0 upgrade providing such a strategic advantage of mobility.

And so if those new, mobily delivered reinforcements want further such special treatment as a ride, they must depend on the commander they've been assigned to to requisition a proper scout car or halftrack for that kind of frontline task.

It is just a thought I had, partially inspired by the 251 halftrack that pgrens are called in from with the German DLC commander, and partially inspired by the constant issue of exactly how mobility is implemented and utilized ingame.