So the way the clones work in 4 is that the skills the clone use are the ones in your quick on.

So if you only have the shadow clone skill hot keyed and potions. The clones will, Do a full basic attack combo then summon shadow clones on their own.

But if you are worried about the game crashing from the infinitely spawning clones. The clones need to do a full basic attack combo before they can use a hot keyed skill. So only the clones in attack range of the enemy can summon another clone.

So if a clone can't hit an enemy they will idle until they disappear.

I almost beat hard mode with only clones.

You cannot beat the final boss with only shadow clones because the game will crash. The final boss can't clear the clones fast enough. So I'm trying to add other skills in the mix to slow down summon rate.