As a general rule the more gunfighters the better no question about it. What if you have the goods, the light weights don’t have anything worth stealing and your opponent knows it.
Against an aggressive trained opponent I could foresee events/tactics that would mitigate a numerical advantage. Like exploding ordnance and multiple coordinated attacks, infiltration through the defense perimeter. Lack of training and poor coordination of responses. No com’s. Long range sniper fire combined with infiltration. Fire bombs. Opponents with night vision. Just to name a few.