Brown spent much of last season on loan at Batley, and former Fax coach Karl Harrison concluded a deal to bring him to The Shay just before he left to join Bradford Bulls as assistant coach.
“I’m not sure why things didn’t work out for him at Leigh, but he’s at the stage now where needs to settle down and enjoy his rugby again.
“He is a big, strong player who will add some size and speed to the backline. We’ve got three specialist wingers in Alex, Tommy Saxton and Gareth Potts and they all bring something slightly different to the team.
“I’ve been impressed with what I’ve seen of Tommy; he gets his nose through the line and gets the team moving forward.
“I’ll be looking for Alex to do something similar and I’m sure it’s going to be a great competition between those three for the wing spots.”
Marshall has also added to his backroom team, with long-serving Swinton player and coach Marlon Billy being appointed as his assistant for 2015.
“Marlon has been pretty much a one-club man, which says a lot about his honesty and his strength of character,” said Marshall.
“I spoke to a few people, but Marlon showed a lot of desire to come here and he’s excited about progressing his own career as a coach.
“I played with him at Swinton, coached him at Swinton, and he’s someone who will do a good job for us.
“He was a back as a player, which I felt was important, he’s reasonably local and he’s got a good knowledge of the Championship, the teams in it, the players in it.
“I used to bump into him at Warrington when Swinton were training there and I’ve had a few conversations with him about coaching.
“His philosophy fits with mine and he’s not afraid to ruffle a few feathers either, which is good.”