The main point was, that it still was an amalgamation of various French and Imperial fiefs, not a unified entity. In fact the Habsburg Burgundian Inheritance only got a unified inheritance with the Pragmatic Sanction of 1549 by Charles V.
However the De La Marck claim comes from Mary of Burgundy, a daughter of John the Fearless. Whereas the Valois-Burgundy-Nevers claim goes back to Philip the Bold. In other words in the fiefs, where there can be inheritance through the female line, the house of De La Marck actually has the stronger claim.
This also means things can become even more complicated, gains made by Philip the Good and Charles the Bold could also go to different heirs.
Interestingly a Valois-Burgundy-Nevers heiress, Elizabeth of Nevers, eldest daughter of count John II of Nevers, was married to duke John I of Cleves (house of De La Marck).