Even in the most technical sense, no he doesn't; he moves from P to DH. Again it's a good rule that lets a special player stay on the field for longer, fans get to watch him play more. And if that particular bit bothers you then really there's not much debate or persuasion to be had here.
You're probably right but plowing thru the weaker sections of his novels does make the good bits even more rewarding. Also he was a brilliant reader of his own writing, a rare separate talent.