By default, the "X Random Enemies" scope in RPG Maker's skill database is the only middle ground between single-target spells and spells that hit everyone. But I was disappointed the first time I tried it and saw that it could hit the same target over and over - in general I've found this makes such skills much more powerful against a single enemy than against groups of enemies, and creates a strange divide where either the skill is extremely overpowered (compared to other skills) in boss battles, or is nearly useless in standard fights, depending on how you tune its power.
It's especially weird since I can't think of a single professional game where "random enemies" scopes were implemented as such. They almost definitely exist, but they must be rare because in my RPG playing legacy I've either never encountered it or have forgotten the few that did use it.
In one of my games I tweaked the code so that such skills can only hurt an enemy once per cast; subsequent hits are ignored (I phrase it as, for example, "Hits 1-3 random enemies", so the player doesn't feel cheated). In another, I have a couple spells that hits a random enemy, but the spell disappears for the rest of the battle if there's only 1 enemy left after you use it - so it provides the greatest value when you use it in a situation where there is a level of randomness you have to manage.
So, how do you manage these potentially balance-breaking skills? Do you change coding / use scripts? Do you do something clever with the formulas? Do you just let the balance fall where it may? Or, do you avoid the "Random Enemies" scope altogether?