Nah; healing is still self-only. They regenerate over time, though. There are a few limitations like reduced damage and no special attacks so things don't get too overpowered in your favor. The idea was mostly to give "lured" enemies a purpose other than following you and getting in the way.
Also, some enemies won't fight ones they "like," and if you kill one in their presence, they'll turn on you. It's really more about simulating an ecosystem than having combat pets, but they can definitely help in a pinch.
The real reason I went ahead with enemy in-fighting is that there is one certain secret character who has a very different play experience from the others, and being able to pick up a legion of followers will just add to that experience.