Complex sentence: During his life, Castellano was able to set up his sons in successful businesses that made them legitimate multimillionaires; however, their companies benefitted from their father commanding a network of over 350 "made" members and hundreds of more associates.
Split into simpler sentences: During his life, Castellano was able to set up his sons in successful businesses that made them legitimate multimillionaires. Although their companies benefitted from their father commanding a network of over 350 "made" members and hundreds of more associates.