The likelihood of a damage buff for Ewoks is small; after all, they are using wooden and stone tools, and their appearance in RotJ shows their strength as working together as a team to compete, not wielding incredible damage. Their representation in the game has reasonable parity with their representation in the film.
In the meantime, increasing Ewok damage can be accomplished through Mods (Crit Damage, Offense) or by pairing the 4 Ewoks with a toon which provides increased damage for the whole group. Both Leia and Poggle are good options, and are FTP. Lastly, running Chirpa as lead provides an additional damage buff on basic.