If I remember right I used wedge, biggs, SF, ashoka and 5s. They're all 7* and I think 5s is through lowest gear level at 9. Got a little lucky with biggs and SF rotating taunts. My Tarkin was/is still terrible lol. I think he's 5 star g6 and the ship was only like level 7 when I did the challenge.
Used a similar strategy as the others, JCs go first then pick off what you can kill quickly to minimize incoming damage. Obviously the dispel by ashoka and 5s should be used on the targeted taunts by mace and plo after the JCs are gone.