It's kind of an odd thing the relationship between the campaign map units and the same units in RTS gameplay. They hold much greater significance in campaign mode but little in RTS mode considering how easily they die.
Part of the problem right now is the maps. Most conflicts are 1vs1 on a 4 player map. Not a problem on an individual basis but it prevents small scale conflicts. It seems silly when you move in 5 troopers against an enemies 3 grenadiers on the campaign map, that the battle could potentially turn in to a full on war with devastators, balloons, ironclads, and imps.
Yes, I feel the same. It's an odd discrepancy, somehow.
In campagin mode, every unit seems important and somewhat expensive, then you switch to RTS and suddenly you build 10 times or more of what you brought with you into the battle. Why is it so difficult to build them in the campaign then?
Unless you bring much much more units than the enemy, you have to build a base, build more units and only then you can attack.
Obviously, it's possible to explain it away, but it's a bit odd.
Of course, it might be that in the SP campaign we will see much more 1vs1 maps with less resources, with potentially smaller, slower battles as a result, making the initial units matter much more.
We will find out, I guess.