I think that it's also worth repeating what was said about the importance of the order of succession and legitimacy in France. From the time of the Hundred Years' War onward, France is almost unique in Medieval Europe in that the constitutional theory surrounding the succession to the throne is highly developed.
France may be unique in the degree to which the rules were followed, but the rules were not unique to France. The many instances of foreign princes succeeding to hereditary thrones, and of bits of territory held by hereditary possession for centuries argues otherwise.
Consider the preposterous inheritances of Charles V. Not just the extent of them, but the variety - from whole kingdoms down to minuscule counties, scattered across half Europe. Yet his title was automatically accepted in all these places.
France is not England and it has a completely different set of precedents, traditions and customs--in other words, you could never get something like the Wars of the Roses or a Henry IV or Richard III style usurpation (at least by this time in history).
Even in England, neither of those takeovers worked out. The Lancastrian claim was dubious, and by Shakespeare's time that was universally accepted. Richard's accession blew up almost at once.
Then England accepted a Scottish king of dubious parentage. (Mother recently executed by England, father a debauched goon murdered with probable mother's connivance.) But he was heir by primogeniture.
The accessions of William III and George I are both examples of the importance of blood right. (Parliament did not dare displace James outright, they waited till he ran away; and they dared not go outside the royal succession by blood.)
It's also important to remember that about a century before this, the legitimacy of Charles VII was questioned and he was actually repudiated by his mother as a bastard. Still, he managed to overcome his enemies and maintain power in the far more dire circumstances of the English occupation.
Excellent point - I hadn't known this.