1) Teebo will stealth random allies (which prevents b2 from gaining tm from counter atks) and remove tm from central droid (and side droids when they come back)
2) Luke will damage it and remove tm as well (side droids as well)
3) Han will erase and stun critical droids add and damage the centrale one (also reducing tm on B2 with his basic atk)
4) Scarif will get the cannon shot and revive himself (the more rebels present the higher health he gets when he revives 20% per rebel and his basic atk gives 15% tm to all allies)
5) Nebit? Taunt and die? (No, never die. I had him taunt between cannon blasts to take any damage that may have been intended for Teebo as Teebo has the worst self healing capabilities of the bunch and then his call assist would trigger Han or Luke or Teebo to atk and reduce tm more)
I take out the side droids and then focus everything at managing b2 tm trying to have my toons stealthed when they atk. I put up SRP taunt just before the tank blast, which sometimes kills him and sometimes doesn't. As soon as it's nebits turn I have him taunt or call to reduce tm, depends on b2 and where his tm is at.
Hope that clarifies a bit.