Threepio can be heroic.
His first thought before being blown to bits is to warn the others about the troopers in ESB.
I always loved that moment.
You get a little glimpse of the metal man behind the cowardly programmed veneer.
As their 'god' it makes sense that he would lead the Ewok charge but it might be possible to use other Tony dialogue (maybe from the Radio adaptations) to make the scene less annoying.