I don’t think people realize that Capaldi is not going to be Twelve, he’s going to be FOURTEEN. Hurt’s Doctor has reclaimed his title and is now nine. That makes Eccleston’s Doctor Ten, Tennant’s Doctor Eleven, Tentoo’s Doctor Twelve, Smith’s Doctor Thirteen, and Capaldi number fourteen. In the world on Eccleston’s doctor and the two Tennants however, they are not aware of this change, so in their realities they are still nine, ten, and tentoo (ie. eleven since creating tentoo took a regeneration and just because he has one heart doesn’t mean he’s not a Doctor) But since Smith’s Doctor, which we know as Eleven(even though we should’ve already been calling him Twelve because the real eleven is Tentoo), has change history and helped Hurt’s Doctor reclaim the right to his name, Eleven has successfully made himself Thirteen, and Capaldi must now be Fourteen. I suppose a lot of people might not want to consider Tentoo a part of the mix since he now exists in a parallel dimension and is not really a part of the Doctor’s reality, but even if that’s the case, Capaldi would be Thirteen (but I still think Tentoo counts since it took a whole regeneration to create him).