I run this team, Ackbar is G11, BB8, Ventress and Thrawn are G11, CLS G12.
I only get close to being in peril when i mistime ventress' Secret Intel/ ID Buffs and cannon is about to strike.
Ackbar is somewhat better being dead due to all assists calling CLS, but i kinda enjoy having him to spam Tac Genius and the Cleanse for extra ID cooldown reduction (more often then not, BB8 uses up TG, casting SI twice in a row and healing up any damage the cannon gets thru his protection.
What i also like to do, is run a chirpatine attack before this team, so i can shock and Cackle all the droids to Red health, and have a quick boost to ventress' attack when her turn comes up.