You can farm St Han relatively quickly and like RJ_Brando mentioned, you'll see immediate results. I'm not sure there are any specific synergies between ST Han and the Ewok squad. In the meantime, you may want to begin farming RG. I think he fits well with an ewok team because they are fairly slow and RG's taunt that occurs outside of his turn can draw fire away from those little teddies before one goes down. And once RG gets burned down, you may see him pop up again