Uhh, right now, I have a typhlosion, an ampharos, an umbreon, a dragonair, a sandslash, and a noctowl. Although I don't keep them close in level at all, so I was mostly just using my typhlosion (who got to level 60 by the end of the pokemon league) and a bunch of healing items.

I'm kinda curious about your Jade theory, but also a little bit afraid.