I can't be of help re: Benjamin's descendants - I don't have access to the 1930 census, which would probably help.
But, I believe I have found Benoit's ancestors.In the 1910 census, next door to him is a "Hufrazen" Hebert, age 80, wife Philomen, age 69.In 1900 this man is listed as "Enfrance".I thought he must be Benoit's father, but this name puzzled me and I couldn't find him in any other census records, so I went back to WorldConnect and looked at the Benoit Hebert born 9 Jun 1864 in Iberia Parish.Voila! His father was Euphrosin, b. 1835 St. Martin Parish and his mother was Philomene Maillard, b. 17 Jul 1838 St. Landry Parish.And there is more info on ancestors further back.So do look at this.