That's way too much IMO, and precisely why I think we might need a navbox that doesn't go immediately after the infobox but rather at the end of the page. Besides which, your version lumps in future incarnations and parallel universe versions in one section, which is less than ideal.
@Toqgers, I do insist that the Morbius Doctors could just as easily be the Other as they could be the Timeless Child; both would make them past versions of the pre-Hartnell Doctor. And again, there is the issue of some sources presenting a version of events where Hartnell wasn't the first regeneration and knew it, sans "regressed me back into a child" shenanigan, which seems like yet another account to me.
@UtherSRG, I like the term "Splinter entities", but yeah, Danniesen is correct that with all the various accounts of who the Valeyard is in place, it's not really T:NPOV-compliant. Also, "future incarnatiosn" seems to go against our end-of-universe perspective.
Conversely, I don't think there remains any reasonable doubt, at this point, that the Curator is anything other than a far-future incarnation. He doesn't belong in "Ambiguous" anymore.
Keeping a separation in three, I propose:
This seems a lot more manageable.