works 100% for me
if your are bballing collectors keep your distance watch your bball do not let it any where near the collectors.
best of all select that ball around middle scout and tell it to dock then re-guard middle scout the bball will then chose a new target the nearest target of highest priority. [IE coll with orders to kami the bball so they can scuttle it inside.]
also u can just use sphere and box every collector and controller on the screen too.
only time i ever lost a swarm/bball/sphere to a coll bomb is if i was not paying attention to it or i didnt care cause i didnt need those fighters cause i already had the game won or something like that.