There is both a generic jawa and a specific jawa engineer quest. Currently I believe the only way to complete jawa engineer is to use JML and call him to assist with the inherited teachings special ability, as the jawa engineer will be the one to deal true damage.
Just evidence that the devs don't actually play their own game. Seems very odd to gate something era related behind owning and using a niche interaction with an unrelated GL. Definitely both a "we didn't test this at all" and a "we don't actually play the game so we didn't know how jawa engineer's kit worked and couldn't be bothered to read the kit ourselves."