I'm actually rather disappointed that Raimi isn't directly more of them, or even most. I know TV is often considered to be beneath movie directors, but it's still his brain child for the most part.
Well, it's not that he thinks TV is below him. A large chunk of his fortune comes from the Hercules/Xena franchise, after all. It's just that as much as he loves Evil Dead, like any Hollywood big shot, he's still probably focused on producing that (which is already a huge job) and juggling any number of other projects. So he's in charge of Evil Dead but can delegate directing duties, writing, casting, etc. And he probably has final say on the episodes anyway. Directing would be nice, but a show needs a visionary to bring all the pieces together, including the director. Thus, he serves a greater role of responsibility as the overall head than as director.
It's almost as if he directed the first episode just to tell his staff, "See, this is how you do it. This is the instruction manual. Now get to it."