Obviously by Cleves I mean the United Duchies of Jülich, Kleve and Berg. And by a Frenchman I mean one of the late François de la Marck, duke of Nevers' sons surviving.
OTL he had two sons, François II and Jacques. But both died without issue. Françoìs II was married to a princess of Bourbon. So, assuming all things go reasonably OTL in Cleves (there's still a succession war due to the duke dying without issue), if François/Jacques are still alive or have surviving male heirs what would the repercussions be?