I really enjoyed using him in Tile Wars, a few years ago. I put him in a squad with CS Yoda (whose CE allows allies to reroll failed saves), and pushed him into the midst of my opponent's squad, where he used Draw Fire and Bombad Gungan to cause glorious chaos. And that squad also used Mace because...Mace.

The key against JarJar is to not place your guys within 6 of him...shoot him from distance and let him use Bombad to push the damage onto his allies, if he wants to. But what if your opponent runs him way up into the midst of your people? Then ignore him and go after your opponent's real threats. JarJar is not a problem if he's isolated because you can ignore him and move away.

He becomes dangerous when he's in the middle of your squad WITH the rest of his allies nearby. You can't just walk away while they're laying the smack down on you, and yet it's dangerous to attack your opponent's real threats because Draw Fire and Bombad Gungan could make things turn bad real quickly. [And if you have AoE abilities (flamethrower, Mira's grenades) then SPREAD OUT before attacking!] JarJar is especially troublesome if you're playing a melee-only squad and your opponent has JarJar and at least 1 or 2 beatsticks that cannot be ignored who are all up in your grill, because he can run one of his attackers to attack your piece, then run JarJar beside that same piece and his piece so that if you attack that piece, he can use Draw Fire and then Bombad to make your guy attack himself.

So in the end I think you can either shoot JarJar from distance while none of your guys are within 6 of him, or ignore him and focus on his dangerous allies. If he and his allies are all up in your face, then you'll need to make good use of targeting rules so that he is not targetable (and therefore Draw Fire cannot be used).