Question on Crusader DE DLC

I'm trying to buy this game and I'm completely new to it.

I see that there are 4 DLCs, but seems like all of them only add AI level(?) and single player missions. Are there any DLC with new units? If not, do the devs have any plan to release any DLC with unit addition in the future? I saw that they added 8 new units with the release of the DE version but I feel like addition of extra units can make this game more complex and fun as a strategy game.