The odds are againsts you from the start at 3 to 1. You are taken totally by surprise. If you put one shot on each of the moving targets and they are one shot stops then you are way over the top. Jim Cirrilo and the members of the NYPD stakeout squad were waiting for the BG's and they were carrying everything from shotguns to .45 auto's and numerous handguns each and they didn't always get instant incapacitating shots. You are face down on the ground with two BG's in one direction and one in another. You are entering into a gunfight with 3 armed BG's who appear to have an idea of what they are doing in regards to their plans and have completed them in 35 seconds. During force on force training with multiple BG's most of us do not get hits every time we pull the trigger and we are firing multiple shots per BG and those hits are not all CNS hits and we are being shot at and hit. During timed reactive target training with live ammunition the odds are better because the stress level is lower and no one is shooting simmunitions back at you but again multiple shots per target including hostage scenario targets and not all shots are CNS shots.
So my personal opinion and it is only my opinion is that it would take more than a 5 shot snub or a .380 pistol to successfully deal with the robbery and the 3 BG's that actually happened and the way it happened with the limited video information we saw. All bets are off if they start executing the clerk or those laying on the floor. That's why I referred to it as a worse case scenario.
Just for information purposes I carry a Glock 19 or a Glock 23 off duty with a Diamondback .380 BUG and in that situation I would want a shotgun.