I think if you return to the text and the author's stated intention you will find the Ewoks do slaughter the Imperials while the Rebels, when capable, fire some laser beams and get shot in the arm or robot (serves them right for not painting their robots green if you ask me).

Nothing too wrong with that if the Ewoks are a fierce warrior people and not slapstick comedy teddy bears capable of laying magic traps in a matter of moments under the full gaze of the troops that will be killed by them.

Jedi stinks.

The good moments it has are tied down by the stench of the sort of "It'll do", "It's only a movie", "It's for kids" mentality that would later lead to the worst prequel trilogy since... ever!