I interpreted sustainable as referring to staying in the Premier League after promotion rather than anything financial. Which, to me at least, explains his lack of interest in playing to the “strengths” of players like Gallagher and Travis, who aren’t good enough at this level, let alone the next one. I’ll be very interested to see who he ships out this window and the next. By talking about needing multiple windows, I think he’s basically told most of the senior players they’ll be on their way if they can’t do things like control and pass the ball.