If I had the rugby league talent that Ennis has, I'd be wanting a much better deal than that - fancy waiting around 5 years for a spot at Hooker when you can just adapt your game to a different position?
Ennis is far too good to have waiting around in lower grades masticating on peanuts while we sort out where he'll go. He'll be in first grade next season, off the bench for a few games and perhaps given a go if injuries/representative honours drain the backline a bit.
There will be tough competition for bench spots next year - guys like Lowrie, Price, Tanner, Newton, Woolnough, Quigley etc will all need to maintain their form to try and keep their regular spots on the bench. Thankfully for them (but not for the side) injuries have meant that most of these players mentioned are either on the bench, in the starting side, or else part of the injury list.