Mod GMY for speed. If your GMY is the fastest in the battle, then he can get the protection up going, which makes Kenobi taunt. This will contain DR’s fear and everything will be much easier.
If he’s not faster, you can still win. Just try and save Padme’s heal so you can do it right after Bastila does all her debuffs. That will get lots of protection up and courage going.
Overall, it just takes practice. Save Padme’s heal for when you absolutely need it, or there’s lots of debuffs to turn into protection up.
Padme should be fast. But also tons of health. Kenobi, just lots of health. Ahsoka: Offense/cc,cd and health. JKA: Crit chance/damage and speed helps a lot too.
Kill Bastila first, then maybe DR or HK or Marauder if he’s there. Save Malak for last.
Hope that helps. :) have fun