Thanks everyone,
Everything works fine. I even copied the Face Codes, so the BKH look like the Desert Bandits. They are now exact replica's of the DB in terms of skills and items. Only BKH still give me 180 experience, while DB give me +- 150 (I think).
Is this due to the fact that skills (riding, throwing, etc.) aren't savegame sensitive?
EDIT: Just read Articulo's post. That answered my question. With weaker equipment the BKH are much easier to kill, so that's good enough for my savegame. Seeing armies of 140 BKH with 400 prisoners just didn't make any sense to me. Especially when Jabbar the Bandit has 10 armies with at least 40 BKH per army following him. Why are they still in the game? The other regions don't seem to have to same insanely strong bandits.