Ignoto
Peter Sullivan (51)
It's hindered development for players in that blindside/number 8 position and negatively impacted on the Wallaby depth and options for that role.
I don't really accept that those guys hindered the development, more the talent just never came through. Cottrell is the only one in the last few years that has shown promise but he just hasn't quite gotten to the next step of hitting the Wallabies. Quirk and Browning at the Reds are too short and similarly haven't developed enough (both had ample games before Thomson and Tui).
McMeniman was our real guy that meets your requirements, but his body never stayed fit for long enough.
Leroy would be the closest that gets to what you're after, but he'd have to lose 5-10 kilos and who knows how much that'd affect his game.