I was curious as to why Hugues II & his wife would name 2 sons "Hugues III" when neither died young & both married & had children. So, I went to the available sources (free & online).
Geni is the only site that mentions Hugues III of Mon(t) doubleau as the son of Hugues II - except for online family trees. He was born 970, but his father was born ca 920 (Geni) or 905 (Wikipedia) - either date would make it difficult for Hugues II to be his father.
Then, there are the other problems with dates, spouses & children for this line:
Hugues I 890-939 (Geni & Wikipedia)
Hugues II ca. 920-990 (Geni) or 905-990 (Wikipedia)
Hugues III ca. 960-1016 (Geni) or ca. 932-1016 (Wikipedia)
Herbert I (son of Hugues III) ca. 984-1036 (okay if 960 is a valid date)
The family trees give spouse names for Hugues II & III - Geni gives them different wives & Wikipedia maintains that they are unknown
The children of Hugues II are listed as:
Hugh III, Count
Fulk of Maine
Herbert "Baco" of Maine
Geni omits Fulk (Falcoin/Foulques), but he is mentioned in the About section of Hugh II. Some sources throw in a daughter
I think this whole line needs review &, at least, that Hugues de Mondoubleau should be detached
