Have you guys found the counter steal button yet? it is where when you fight you counter and you get everything they have, better then looting them and you don't have to kill them unless you want to also much faster.
Unless it is a Agile guard, you can counter steal. Don't know about Janissary's though I don't think they can either. Also if you press the attack button right after stealing, you instant kill the guard that you stole from.