with the handgun, on "plinker' type shooting, at MUCH greater ranges, and FAR too slow speeds, than is realistic for defense. If you ever HAVE to fire, you are NOT going to slow down in order to get "better hits". what you are GOING to do is trip off rounds FASTER than you EVER have, so you'd BETTER learn how to DO that, and STILL get chest hits, to 10 ft or so. THAT, and EXTREME speed of draw, etc, are what you should be practicing, not rows of plates or tin cans or torsos, at 10m and further, taking 4 or more seconds.
The odds are at LEAST 3 to 1 that if you HIT one attacker, you will NOT have to hit any others who MAY be present. The odds are well over 50 to 1 that you will not have to hit more than 2 of the.
So don't BOTHER with practice scenarios that involve firing at more than 2 targets, with your handgun. It won't happen, and if it does, only luck or cover will save you. So don't waste precious range time and ammo on such bs. Instead, do most of your practice at home, using dryfire, primer only wax, CB caps in the .22 unit, working on EXTREME speed, at arm's length ranges, out to 10ft, for first round hits.
Useyour actual range time for confirming you can do just as well with centerfire ammo, on same ranges, targets as you used at home, and same TIMES, and that you can get REALLY swift repeat hits, mostly on ONE guy,, but a bit of time and effort should be spent on getting hits on guy #2, also.
shtf, you will either have your auto rifle, or you will be dead, so skip the bs about "25m pistol will be a needed thing, for shtf"