Actually, Grazzle with one other player is pretty potent, because he doesn't have to divvy up his healed cards. Grazzle is my fiancee's go-to healer. Basically, any time she gets a cure in her hand, she heals everyone the next turn. In a six-player game, the cards healed have to be shared among five other characters. With just one other, Grazzle can just pop one or two cards any time the other player wants a heal-and-shuffle.
I do, however, see your point about Crowe being a less-than-ideal partner. I was just figuring, if you've only got two players, and one's a rockin' Divine caster, the other should be combat, anti-barrier, and/or Arcane. Since Crowe is two of the three, I felt ok with that.
So, yeah. Just about anyone and Grazzle would be a decent pair.