It's even better because Sherwood is the reason we have this model. He advised Power that there was a gap in the market for young Academy players to be developed and sold on. I'm paraphrasing but there is an early Power interview in which he said so.
In the case of Byrne and Luongo, he was right. I've said before that currently the model must be failing in Power's eyes, not becasue we're shit and on for another relegation struggle, but we've nobody worth selling on.