I always get these reactions to the number of rounds, etc. Check with your local LEO as to how many firearms (and other tools) he/she carries and the number of rounds. In my area, the LEOs typically have :
1) primary handgun
2) back-up handgun
3) bug handgun
4) AR-configured carbine
5) 12 gauge shotgun
6) taser
7) baton
8) bullet-resistant vest w/ 3mm titanium plate
9) radio communications
10) back-up up the whazoo
Well, that rather leaves me feeling comparatively like my skinny posterior is hanging in the cold wind, and nobody to cover me, or back me up. If my weapons fail (or components) I'm screwed.
The critical factor is not the number of rounds available, it's the number of magazines in case of a magazine failure, or 3. In Advanced Tactical we were taught that it the pistol fails, likely it is a magazine failure...drop it, and load a fresh magazine. If the second magazine also fails, drop the pistol and go to the back-up. If you physically drop the magazine, draw a fresh magazine. Finally, we were taught not just 1 shot, but double-taps and triple taps. We also did several exercises involving emptying the magazine into the target.
I assure you, for where I travel, and the types of multiple attackers on a single victim, I am not over-packing.
Respectfully,
Geno