I don't know if this has been said and im much too lazy to look it up, but it think it would be super duper if there were more types of quests. Some possibilities are:
Ambush- attacking a convoy with a set path that you must stop
Assassination- a single unit that must be killed for a victory, possibly with others protecting it or just a one-on-one situation.
Protection/King of the Hill- protecting a designated area
Bonus: Dance party- I have no idea what this would be, just felt like i was at risk of being taken seriously
Of course, i have no idea how hard such a thing would be to set up, so im just dreaming out loud here.