I'm on singleplayer story, at the mission on the docks--running around the docks trying to find the boat they took Fabiana on--and throughout this whole game so far, there has been a very consistent point: Passos is absolutely useless.
In the stadium mission, he was useless when he had the sniper rifle; he was useless and I had the sniper rifle and I had to defend him; he was useless when we were together at first. I can't remember all of it but the very first mission at the rich man's house--Rodrigo, I think his name was?--I think Passos was useless there, too.
He was also useless for me in the flashback mission when I killed the mobster's son in Jersey, although not as much. He at least killed ONE OR TWO thugs on his own.
Anyway, sorry for the rant. I love the game, but Passos isn't doing a damned thing and he makes me angry.