Honestly, I feel like the gimmicks are actually really more interesting than just raw power. I mean, that's really what I loved about all of Reborn's gym battles bar a few (like old Charlotte where none of my mons could survive an Eruption from Typhlosion).
I guess I'll try to explain what I did with Keta. Lucario, Medicham, and Hawlucha were all on his team originally, and I kept their movesets pretty similar (I think.) Scraggy is there to deal with the Xatus and Swoobats that can easily sweep him, and Heracross as well as Breloom are really just there to abuse the field. I can see where your criticisms come from, I just really focused on the gimmicks, I guess.