Yep, probably fair enough.I think you're being a bit too kind. Most were speculative picks, way ahead of where most thought they would go. That's even true for Cockatoo, but he's obviously had chronic injury issues.
It's true that Brown had bad injuries. Whether he would have justified his high draft pick is arguable. Thurlow had a knee reco but many others have come back from them.
Smedts never looked like it, injury or no injury. He had the most awkward kicking style I've seen in an AFL player for many years. I'm amazed he was considered a top prospect as a junior. Lang never looked like a top 20 pick to me either.
Wells has done great with late picks but not so well with early picks.