i do sort of agree that your level 85 heros shouldn't have to face up against an awakened level 90 hero team in cave. It is kind of rediculous and when you refresh the list you just see the same list. There is a huge difference between the teams you face and in my experience my blue heroes with their third ability were facing purple geared heros with their fourth ability putting me at a disadvantage and making it challenging for me to win.
I have done the plundering and I feel the rewards should be better and I feel they should limit how high of level you face. For example, my level 45 heros shouldn't have to face a level 55 purple hero team with their fourth ability unlocked while I only have my third ability unlocked. It just isn't fair in that perspective. Maybe you can have me up against another 45 team? I would totally be fine with that. My point is that levels make a huge impact in the fights.