Yeah tell me about it. I've been confused why every different task manager shows me different lists of running apps compared to the built in list. I finally found the best task manager, system panel, shows the true running apps list. And It shows what is active vs inactive (cached) which NONE of these other task managers show.
Finally with this app I am starting to understand how android does its multitasking, and I've been trying to learn for 2 months now. I actually got angry once I realized these other task managers were lumping in all the inactive apps together, giving a COMPLETELY false sense of what is truly running and what is not.