I should have been a bit clearer, in using those groups, figures, what have you, I was trying to use something familar from OTL as a sort of analogy to this hypothetical world for purposes of illustration, rather than exact persons or organizations that would exist in such a world.
Just curious though, why is it that the odds of Henry being born are so astronomical or impossible? Colombus would stand just about as long odds given the POD, but it's Henry specifically that you both point out as impossible or astronomically unlikely. I'm not being snarky here, I'm legitimately curious as to why there's so much certainty about Henry specifically? I'll be the first to admit, the history of Iberia isn't exactly my strong suit, but what is it about the Franks changing their rules of succession that completely wipes out Henry beyond any doubt?
Okay. It's just that it would usually be better to say that you were discussing an analogue to a historical figure, rather than dropping Henry the navigator or colombus into the timeline and giving them the same role to play.
honestly, my fixation with Henry was originally because you went out of your way to include henry in your timeline, and how the first criticism of your scenario was your inclusion of him. In all probability, neither has a prayer of being born.
However, this did get me thinking: which person is more likely to be born: henry the navigator or christopher colombus? henry comes from a much smaller pool of ancestry, and is closer to the POD, but is also more vulnerable to the butterflies. Colombus is a bit harder to say, given how even today we don't know that much about him.
The thing about Henry the navigator is that he isnt going to be born, because your POD is explicitly tampering with the circumstances surrounding his ancestors. Henry the Navigator was a prince of the House of Aviz, which was the royal house of Portugal at the time. they rose to power in the late 14th century after a succession war when the current royal house, the Afonsines, died out (the Avises were a cadet branch of the Afonsines, via a illegitimate son). The Afonsines, who established Portugal as a county and later a state, were themselves a cadet branch of the House of Burgundy, via a younger son who left the country to join the reconquista. The house of Burgundy, in turn, were descended from Duke Robert the Old of Burgundy, third son of Robert II of France, who was in turn the son of Hugh Capet, founder of the Capetian dynasty. Hugh Capet, in turn, became King of France when he was elected king following the death of Louis V, the last Carolingian king.
What was the point of that rambling tale of dynastic inheiritance? There are two, and both relate to your POD. The first is that your scenario posits a very different pattern of carolingian inheiritance, which will create all sorts of different political dynamics, not to mention different kings. The last carolingian king in france may die in 900 CE, or 1000 CE, or 1500 CE. In any of those cases, Hugh Capet is probably never going to live, and almost certainly is never going to have a chance to become king of france. And with no hugh capet (or just one who is not king), you have eliminated the house of burgundy, which, among other things, means no Afonsines, and in that case quite possibly no portugal. The second is that your scenario implies that the reconquista is carried out either by the carolingians or by carolingian successor states in spain. this is an interesting concept, to be sure. But it is very different from the course of the historical reconquista, which was launched from Asturias. It will probably be divorced from the Kingdom of Asturias's attempts to reconquer the penninsula, with the expansion beginning in the Pyrennes and in catalonia instead of in northwestern spain. This is an interesting scenario, but it means that even if a henry of Burgundy travels to Iberia to join the reconquista, it will have a very different dynamic (for instance, he probably winds up fighting for the carolingians in the east rather than the spanish in the Asturian successor states in the west).
In short, your scenario removes or alters Henry's ancestors in such a way that they will not exist, and creates a political dynamic whereby even if they make it to spain on schedule, they will not be able to do mirror their accomplishments IOTL.
Colombus may be a bit easier to justify, given how little we know about him. But he faces many obstacles as well. his ancestors may die or never meet as a result of butterflied wars. He lives after henry, so even more butterflies are conspiring against him. In short, he isnt going to exist either. The only real difference is that it is easier to catalogue why henry the navigator will not be born.