Guillaume and Jean Hubert were not related. The family of Jean Hubert was from Bordeaux, where they were established since the middle of XVIth century. The family of Guillaume your ancestor was from Tours. There was three distinct families bearing the the patronym Hubert in the soouthern Province of Saint Dominuge.
Nevertheless, Guillaume married a Jeremian. Marie Robinet was the daughter of Sieur Pierre Robinet a royal notary for the parish of Jeremie and his wife Michelle Navarre. Marie Robinet was indeed the widow of sieur Padirac with whom she had at least one child, Jeanne Desiree Olympie Padirac who was to marry a Sieur Leveque. I hope this information will be useful.