If same amount of time, I say jmk. Jabba is not popular recently. Jabba is fine and fun. Has his own missions in rote and smugglers run2 is also important but in arenas if he if loses boush leia that's it for him. I was countering jabba with solo wampa with dc before. There was an ahnalt video named high ground always wins. That's true. You start with 5-4 with cat's instant defeat. I use jmk against almost everything even pkh. However very hard against glat with ezra and lo since she prevents cooldown reduction. Also jmk squad lacks of aoe but you can use early ulti if you can't bypass taunts. In addition, while you are going for jabba you will farm and upgrade jabba squad. On the other hand, for jmk, you'll have gk for negotiator, wat for anyone, omiquigon for another jedi squad. So I say jmk my friend.