Wouldn't this make it OP, the mind set already has an AoE hold, giving it 2 and especially one that is permanent would be overkill.
if you do really want to make it better I feel 5 targets is fine for an ability that can run permanently but I would increase the AoE on it maybe as it tends to loose hold on targets when they float too far away from each other or get stuck on random terrain.
or maybe on top of the push give it a pull to the center (your target) this way getting all 5 is mostly guaranteed and it can snag more enemies as they die or in case of boss level mobs who just run out to snag other mobs that pass by.