All perk unlocks that are based on game progress are only unlocked on the host's game. Thus if our brother wants to unlock those skills or weapons tied to killing lieutenants, total resistance meter levels or basically anything story related, then he will have to play in his own game to unlock them. Yeah, it kinda stinks, but then you don't have to play on a specific difficulty level to do so, and after a bit of play, easy is really really easy.
As a good note, you can give him the better weapons by dropping them exchanging weapons for one of the ground and having him pick up the good weapon, then go back to a shop and get your weapon back. Since you can complete the game fairly easily with a 1911 pistol and a bow, multiple holsters are just for your convenience and playstyle. So add a second holster and put a m60 LMG in that slot and you are set for pretty much everything with 1911, bow and M60 (suppressed, red-dot and extra mag size of course).
2 people found this helpful