Since everything is geared more towards open posts, department heads will still require an open post per AC but that could count as making the AC.

Example: Let's pretend Sherlock was a department head. (Oh god the horror). I have three characters, Brainy, Sherlock, and Hiccup. I could make AC with stuff for Sherlock and Hiccup. But if I didn't have a Sherlock one up for that AC, and only had opens for Hiccup and Brainy, I'd have to do an additional Sherlock post since he's department head.

So the department one can be folded into making their usual AC, but it still has to happen.