I would not be saying this if he was not 198cm and capable of playing 20% of game time on-ball but I think he probably has to play the next five games as the forward combination settles.
He's a developing tall (at least that's how Dodoro described him) who has played in two different forward set-ups so far. He's shown some signs of the hard working lead-up forward that he could be. While some of his ground level defence has been really good I'd certainly like his hands to improve.
In making the argument I'd say that he basically has the same output as at least one, and possibly two, of the small forwards who are getting less than 10 possessions, kicking a goal and laying a couple of tackles. Hopefully what we see in JLT 3 is Hooker, Daniher and a freed up Stewart to play higher up the ground.
I don't think we need more than a goal a game, 10 to 15 possessions mainly as a lead up half forward and 20% of game time in the ruck for Stewart to be an important part of the side. While he's hardly setting the world on fire he's not actually that far away from what we need.