I really like the missions that involve having little to no room for expansion and you're completely relying on capturing enemy territories in order to get the rooms and minions you need to complete the level. There is one mission on WFTO that is like that, I can't remember the name but it's the mission where you have to rescue another Underlord (before the mission where you defend him)
Are there any maps on the workshop like that? Most of them seem like siege types to me and I can't find one like I described.