Think there is a risk of over analysing last night which was a bizarre spectacle but, given that Stewart already seems to be copping it, I'll take the risk.
I paid close attention to Stewart at the ground last night and it was hard to work out what he was supposed to be doing. Whatever it was it did not look particularly good. In fairness, on the few occasions he was one-out against his opponent or he had space to meet the ball he won a free kick or took a mark (Colyer kicked a goal playing and Stewart missed a couple).
There was little structured movement of the ball forward with a lot goals kicked as a result of the race back toward goal. It's not a style of play that suits Stewart. Langford is a good point of comparison and he was similarly non existent when playing at half forward for the first three quarters (although he had the advantage of being closer to the action). It doesn't really suit any forward who wants the ball on the lead. Brown did nothing forward either.
Kakkle mentioned that Stewart plays like he is 190cm and I think that is probably correct, as a style of player he is like Watts or Gunston, but last night, he seemed to be playing a role like Bellchambers did in 2013. He's definitely not going to play his best footy standing under a high ball and trying to take pack marks, he needs to use his athleticism on the lead or he needs a jump at the ball.
The catch-22 for Stewart is that I don't think he needs Daniher and Hooker so that he gets an inferior opponent as much as he needs those guys so that the focus of the team becomes a more traditional build up through half forward (which we'd have to assume would occur). Unless there is a change in forward play, and given that Daniher and Hooker are still working their way to match fitness, I doubt that Stewart will do enough to play round 1.