Ewoks in a unfamiliar place. Or Hobbits who, if proficient with ranged weaponry have accuracy of near Elvish levels. Add to that, a Hobbit can move with almost no sound. Sorry, on equal terms I don't see the -blam!-ing care bears winning this. Face it, the only reason the Ewoks were succesful in RotJ was because the Empire didn't care enough about the stupid looking sub-species. They had traps, numbers and surprise (IIRC) for the most part on their side. That battle is all I know about in terms of Ewoks. Unless there's stuff about them (Which is now non-canon. Suck it EU figs.) in the EU, there is literally no reason to think they can win.