How many does he have total?
I always liked the idea of Dr. Who incorporation continuity flaws into the show itself.
"The main lead just quit!!!"
"What? How can we make the show now?"
"Wait, let's get another guy to play him- and say the old guy died!"
"Wait, have a different Doctor? Why would the show be called Dr. Who then?"
"Okay, have it be the same guy, but a different life!"
"Hey, that works great! We can do that a bunch of times!"