Having Milford and Barba around Smith is not that far from having Slater and Cronk, besides everything that Hunt would learn from Smith (in the same way Widdop learned a lot, and he doesn't have the talent or vision of Hunt), so it is a very real possibility that getting Smith would deliver us a premiership, or at the very least set us in great shape to win one in the short term.
Besides that, we would get a guy with a lot of RL smarts in the coaching staff, something we all know is a necessity.
Macca is not as bad as some paint him, but he isn't a great/very good hooker either. I do like the kid, see plenty of potential in him, but he needs some serious coaching to get rid of his flaws, meaning a "trade" with Melbourne would be win/win. Besides, like someone said, what's to stop us to throw a lot of Smith's coin at Macca, if Bellyache has managed to get all the potential out of him once the Aus Captain retires?
I am surprised people will let their personal dislike for Smith override the clear benefits his recruitment would mean to the Broncos present and future.