I think you'll see a lot of speed by Manly through the ruck as the game goes on. Williams has a good motor, so he's a loss for Parra pack and Manly have some speedy agile forwards + they lift at home.
Wouldn't be surpirsed if there's a few line breaks in the last 20 due to tired Parra forwards and DCE, Garrick or little Brooks, backing up for some easy tries.