ORIGINAL: diablo1
and the only approach is to concentrate your firepower on one enemy after the other.
That's the way I used to play CRPG's the gold box series and the like. Concentration of power was always the ticket. It would be different if someone would make these tactical games like reality "one shot kills" and then allow for inaccuracy moreso than you need 10 shots to kill this thing.
Jagged Alliance 2 does that fairly well. A sniper rifle will kill most enemies in one or two hits, and a sniper can get off two shots per turn, which if the sniper is competent (like Raven or Scope are) usually means two hits per turn.
I also like to play Oblivion for that... sneak through a enemy-infested ruin and pick off the bandits, marauders, conjurers, necromancers or whatever via sneak attack with poisoned arrows, which is usually a one shot kill except against tough enemies (such as orcs of a warrior class) wearing heavy armor.