It's not a "form dip", that's the problem. Did all the "future immortal" rookies before him have a 10 year "form dip" after their debut year which was 10x what Walsh has shown?
TEAMS FIGURE ROOKIES OUT. Their 10 minute (max for walsh)flashes of talent are what get them noticed, but a game goes for 80 minutes. It also consists of attack AND defence, stupid errors are not forgiven, and it's a team sport. This is all learnt in reserve grade, in the NRL it quickly becomes a reputation and gets further targeted leading to a complete loss of confidence that may never be recovered.
Never guaranteed but given his attitude I will be putting money on Walsh never playing origin unless there are 3+ injuries at fullback and he will not be anything more then a highlights reel player from time to time in the mould of a Bevan French. Brown has absolutely destroyed his career in my eyes, he probably claimed "look what I did with ponga" when he sold it to Walsh but ponga was 10x the player he was at the same age AND I firmly believe he would have been in a better position with his career had he not joined Newcastle.