Yeah, Deck Knight, you're completely right. I simply forgot Swampert's amazing list of resistances. So, Grass/Fire would work both ways: either dishing out damage, and surviving some attacks. Pretty much like... Gyarados? The difference is that the Grass/Fire would never get Dragon Dance, and the STAB moves are different and blahblahblah, but still. It's a shame Grass won't win anymore, sadly.