One of the most annoying parts of the game I must say,but here is a tip.Well before you even go to confront the assasin droids,activate your shields.Then go charging at them with your melee weapon and slice them up.You might even want to stun as well as use force lighting to finish the job on one a lot faster.Then repeat.Every time your shield goes down,keep regenerating them.I hope this is of some help.May the force be with you.

Ion grenades work wonders. If you're really having trouble, send Kreia and Atton in, and hang back. If Kreia dies, well... But, Atton will keep respawning as long as there's at least one more character alive.