OK, it look like I have the Druids and Saxons DLC. If I DL from GG I can forget about Steam for KA. But $10 seems a bit steep for just the other 2 DLC.
You already have both mission expansions then. Afaik, the other two are just DLCs that give you additional units and items.
I'm downloading the demo as I type this. I want to give it another try.