Well, I can tell you from at least a dozen or more hero conjurers that bind works this way, at least prior to 2007. You conjure with no mana, anything, that is angry and put a no mana binding and it will turn before timer is up. You put a 50-200 mana bind on it and it doesn't. I can tell you 100% this is how it worked before. Maybe it isn't a stronger binding but makes them a little bit "happier" at the start like someone said but I am not sure since I can't see the code.