I'm not quite sure what the Grammar Squad entails, but I'm willing to join and lend a hand. I've always been a stickler for proper English grammar.
In fact, I've personally completed and released "grammar mods" for two computer strategy games, namely Galactic Civilizations II and Armageddon Empires. You can find the Armageddon Empires mod (and the readme I wrote for it)
here; as for the GalCivII mod, I'm afraid I've lost track of it at this point. I haven't played GalCivII nor participated in its online community for a while now, and the mod is lost somewhere in the churning bowels of the GalCivII mod database.