Probably things can be made simpler by removing agnatic primogeniture (male to male only inheritance) in France.
IIRC Aragon only followed pure agnatic in imitation of France. France only followed agnatic to remove any chance of Edward III inheriting.
In fact the French adopted a male line system in several steps, with few links to Edward's claims. First they excluded women because of the suspected illegitimacy of Jeanne, the daughter of Louis X (her mother being notoriously unfaithful). Secondly, they excluded sons of women because the heir, Philip of Burgundy, was too young at Charles IV's death while Philip of Valois was in his mid-thirties. Afterwards, all of this was wrapped into the salic law paccage.
In Aragon, they said they had a salic system (since James Ist, I am not sure about a french influence there) but the only occurence was the succession of John Ist by his brother Martin instead of his daughter Violant. This brother before daughter was more common than the french cousin before grandson which ultimately failed in Aragon.
My point being, the laws of inheritance sure mattered, but the safest way to secure a personnal union includes a brotherless old king and a female-line adult grandson. In this situation, the legal system would be adapt. Succession crises only arose when the old king had no direct descendance.