Ahnald did it without T3. I think Mission is a detriment because she drops DoTs which causes Malak to give her fear. She also does damage to Malak when you don't want to. The whole strategy revolve around avoiding Darth Malak. His damage is minimal as long as you keep killing droids to prevent enrage. That gives you time to stack up several armor shreds on him. If Mission assists every time Zaalbar armor shreds Malak it drops his health too quickly. Then he drains the life out of one of the Jedi suspended in the tanks, and you're in trouble.