I am trying to find a story I read a while ago, but I can't remember all of the details. This was probably a short story, either in a collection or a sci-fi magazine. I usually read Analog, Asimov's, and Fantasy and Science Fiction, but I didn't find it in the issues I still have.
Basically there are these enhanced Brute soldiers (I think that's actually what they are called, but I can't remember for sure) that are operated remotely by other soldiers. These are biological brutes, this is NOT Forever Peace by Joe Haldeman. One of the only other details that I can remember is that one of the brute soldiers is thought to be killed in action, but later turns up (I think fighting in a cage match?), and it is discovered that they have more of a mind than the operators were lead to believe. I'm 99% sure this is set on Earth.