Toohey actually says in that article that Watson goes to hooker, Mann to fullback and Crossland to 5/8 when Levi goes off.
That seems like a lot of changes, but all 3 guys go to their best positions IMO.
In the game against Wests in reserve grade 2 weeks ago Crossland made a season high 25 tackles and missed a season low 1 tackles.
That was a game where Wests played a lot of firstgraders and the Knights put up a pretty fair effort as well.
Over the season he has been missing 4 or 5 tackles a game and is number 6 for missed tackles and ineffective tackles in the comp, but early in the season he was leading both those stats, so he is improving rapidly.
He's a skinny 18 year old, so all he can do is do his best against the big boys who will run at him, and hopefully he gets a lot of help.