I haven't thought of a way to make it easy to set up random battles.A good Idea is put a option to Random Positions for Enemies.
It will add more strategie options, and a easy configuration for Random Battles.
And for Bosses, use the option for set-up positions for script command.
It's the same issue with the default battle system: how do you make random encounters that aren't basically the same enemies?
I never came up with a good solution for that before.
Someone did this thing where you set up like 10 different troop configurations, and then the random encounter just picks a random troop. Which is alright. So maybe you would just set up 10 troops, each with their own position configurations defined in the troop itself?