I've played in lots of different play-styles. Bomber, Gunner, Swordsman, a mix of the two. All on elite, and I've never really had a challenge. The only times I've experienced difficulty was when I wasn't full 5* and during shadow lairs. Now missions are just not hard at all. Enemy attack patterns are very predictable and easy to kite.
I think they should add a new difficulty; Nightmare.