That's similar to my favourite solution to this issue Sinister, albeit better explained and thought through. I don't realistically think it's possible at this juncture to introduce a whole new system like that, the game is releasing in a few days and it's not the kind of thing I'd expect from a post-release patch. Maybe if we got a Dragon Knight Saga style update but it still seems like a long shot.
Hopefully adding some sanity to the auto-resolution will be sufficient. If the option to join the battle yourself is limited (which it seems it is and it isn't depending on mode) then it doesn't need to mirror the RTS results that closely and some kind of balance can be maintained. At this juncture the game feels like it's approaching real greatness and every quibble seems important.