Yeah, as long as the titans are taken out, the setup dissolves... But if you noticed, they had multiple bubbles. Through coordination, you might be able to take our 2 def, 3 at most but as long as there is one bubble left, they can survive for that bit. The single titan can FoH his way directly into the center, punch right into the nucleus and take out the heart right there, at which point the rest of the fireteam could use there supers and finish off anything left standing. A DfA perk would be too risky, he'll be shot out of the air mid move. Maybe some special grenades might work? Flashbangs and ability denial ones perhaps...