Truth. It took me a few times to get the hang of that little trick you and GamingBeaver mentioned, but it sure has helped. Thank you.
For me also, the Cenozoic and Aquatic battles are more reasonable. It seems like the game really does base your opponents off whatever your highest level dino is, even if it’s light-years stronger than all your other dinos. For instance, my most powerful dino is a level 30 Indominus with not quite 4000 health and about 1300 or so damage. My next highest dino is a level 40 Tapejalosaurus with 1300 health and 900 damage, and everything else goes down from there. Nevertheless, my PvE opponents are usually about the level of my Indominus, which means not much PvE for me (exception: on the “rare only” or “common only” battles, the opponents are much more reasonable. Unfortunately for the “super rare only” battles, I have a level 30 Giganocephalus that is way ahead of all my other super rares, so I run into the same way-too-hard opponents for “super rare only” battles."
As we’ve said elsewhere, moral to the story: keep all your dinos at about the same health-damage level, and don’t let any of them become significantly more powerful than the rest!