Yeah. Good to know I was not the only one with these thoughts.
I remember thinking: Well, I cannot put the zone in between those buildings, for vehicles will go mad. I cannot put it in front of the buildings, for the units will have no cover at all. So then I put the zone at the back of the buildings, then hopefully some of the infantry will take some acceptable positions, but the vehicles will just be idle in the back, unable to see anything...
Maybe on the software side it can anticipate a little? Like automatically do this or that, or avoid this or that, when the order-zone has lots of buildings or forest.