Dathcha: Great with Luke and Han in HAAT, as you mentioned.
Jawa Scavenger: Very good in HAAT p2 and p4 with Clones. Because he has some health steal, he'll heal up after the tank AoEs. He also guarantees an extra attack with Rex's group attack, and if it happens to be Rex himself, that will put his TM at 100% and allow you to group attack again.
Jawa Engineer: Works great with droids if you don't have BB-8 yet. BB-8 only speeds them up at the start of the battle, but Engineer would rarely get a second chance to give them bonus TM, so it's a push.
Chief Nebit and generic Jawa are a little lackluster. But a full Jawa team is surprisingly decent in Territory Wars on defense, or on offense against mid-tier teams. Obviously they won't beat any meta teams, but if your opponent actually uses a meta team against them, you're definitely ahead on the transaction. I'd recommend using a droid instead of Jawa Engineer, though, since Chief Nebit can call it to assist and get some extra benefits. IG-86 works well-enough. Put Jawa Engineer into a team with four droids, then put BB-8 in a Resistance team with Jedi Rey. That's three teams, ranked from really good all the way down to pretty okay!