VARY THE DISTANCE
I also train in engaging multiple targets at varying distances. Conventional training when facing multiple assailants is that the closest should be engaged first. However, if the closest has a handgun and one a few yards farther away has a rifle, the best tactic would probably be to engage the farther one first.
I shoot at a range with hanging targets and pepper poppers between 10 and 35 yards and often practice moving among them putting quick double taps on targets at different ranges. Sometimes, I incorporate moving behind cover.
By training at different distances, not only will you improve your shooting skills but also your reaction time. You will also learn more about the capabilities of your carry guns so that you can judge at what distances you can use effectively them to engage an attacker.