Actually, that tended to cause issues in single player as well. Problem is, if you had an enemy stack with the chance to kill a unit outright (e.g. medusas) they could potentially use that ability against your hero, no matter how high their level and how tough they were--and since there were single player missions you would instantly fail if your main hero died, well, you can see the problem! Somebody at NWC really didn't think that one through. Other than that, though, I actually liked having your hero be another unit on the field--it was a nice change to the gameplay that might otherwise have been a bit stale after three iterations of the same thing.