when i do campaine battles(all by my ownsome though
) i use the map system and construt two bases for the final battles, and then just construct the other battle fields on the fly.
i have advice, don't use the tree system,
aka if blue wins the battle they advance and the next battles at place x if red win then the next battles at place y.
and so on, this makes very long compains(more than 5 battles) hard.
since you need to work out a result for each battle.
if blue wins then you move to battlefeild 2 if red win go to 1
1: if blue win go to 3, if red win go to 4
2: if blue win go to 5, if red win go to 6
thats two battles with 6 diffrent possible places
the next round will need anouther 8 diffrent battle fields.