The way I see it (and I could be wrong), but Brianna was worse.
Both mothers were "using" their sons, but Brianna's was more sinister. D'Angelo was a pawn to his own mother. She was fully indoctrinated in the game, and to her it was more than money. That's what all the "family" stuff was about with her. He was a pawn on the Barksdale chessboard and she was moving him (or urging him on how to move) for all of their benefit.
Namond's mother used her son, but she viewed him as more of a piggy bank than anything. On the surface that might seem worse, but it isn't. When she was trying to get money out of his father and other hustlers, she used him, so when that didn't work, she told him to go sell, but if a talent scout came around and said I'm looking to start a rap group and I wanna sign your son, she woulda done that. Same with ball, same with anything.
If D'Angelo was a lawyer, his mother would make him defend the fam. If he was a doctor, his mother would make him pull bullets outta soldiers. Whatever he did, wherever he did it, he woulda had to do it on behalf of the Barksdale clan.
Namond was a piggy bank, and whatever he did his mother was gonna bleed him, because she just wanted money.
D'Angelo, regardless of what he wanted or what he tried, was going to be pushed into the game, because his mother believed in the streets.
To me, that's way more sinister.