Many times on Cannith when the server hasn't been that full, I've been in a group with one or two other people. Often we have no cleric, and we're at a level too low to be able to have all our characters fully loaded with potions and wands and whatnot.
So one of us buys a cleric hireling.
Alright, so we're in combat, and stuff starts to go south. Let's say I'm controlling the hireling, and I tell him to heal me. Nine times out of ten the hireling decides he has better things to do than heal me, like stand there and watch us all die.
Then a little bit later when somehow we beat the mobs off, we get to a shrine. I tell the hireling to use the shrine, it says ok and runs a few feet towards it. Then it turns around and starts leaving again. I have to repeatedly tell the hireling to use the shrine, and sometimes it still doesn't listen because they apparently like to be dead.
So, I have two suggestions:
1. Hirelings are stupid. I know this, you know this and I'm pretty sure there's no one who's played who doesn't know this. They don't move out of the way of a mob when they're ordered to cast a spell like a real player would, and so I don't think that they should be required to make concentration checks like a real player would.
2. Hirelings apparently loathe listening to the person who bought them, so give the option to the controller of the hirelings to take direct control of it, completely bypassing the Hireling AI. As in the person's character is immobile, just like the person was AFK, and they have direct control over the hirelings abilities, such as taking over a wizard hireling and being able to cast repair moderate damage on a fellow warforged.