That’s a good way to do it. In fact for probably the first 6 or 7 months of the game after launch I just used the eight highest level dinosaurs I had. That did me well for that time.
As for what I’m doing… well… I’m not a competitive player. I have no desire to climb the rankings. I picked up JWA because I wanted to play dinosaurs not hybrids. You will also notice that there isn’t a lot of variety in the dinosaurs used either for the most part. I had loads that never saw the light of day so I decided to just play theme teams for the fun of the game. Win or lose I would have fun playing prehistorics and seeing how specific themes worked out. The only caveat, Stegoceratops (last week and next) which got a shoehorn in, was that the only hybrids would be the two canon ones from the films. Their role is give me a chance to not freefall if I have a bad theme and to stop me getting low enough I pummel lower players on the way back up.
Ultimately, for me, its playing the game the way I want to. Actual prehistoric animals and for fun.