Well Haros have shown up in 3 different Gundam universes. The original Univercial Centery, SEED's Cosmic Era and 00's Anno Domini. In each of them they're all different. They're the most useless in SEED's timeline.http://en.wikipedia.org/wiki/Haro_%28character%29
This will better explain the 3 types of haros and their functions and answer your questions.