Considering the relative prices, I would go Atley over Gaff.
Looking ahead, we've got these spots filled:
Tall backs: Naughton, Young, Trengove, Adams, Roberts
Mid-sized backs: Wood, Cordy
Rebounding backs: JJ, Williams, Crozier, Richards, Biggs?
Inside mids: Wallis, Libba
In/Out mids: Bont, Macrae, Mclean, Dahl, Dunkley
Outside mids: Hunter, Dale, Daniel, Lipinski?
Rucks/2nd Tall Forward: English, Roughead
Tall forward/2nd Ruck: Boyd, Schache
Mid forwards: Gowers
I would suggest they should all be around in 3 years, and at least in our top 25 players.
That leaves:
Morris, Dickson, Picken, Redpath, Clay Smith - probably all retired
Collins, Jong, Honeychurch, Webb, Campbell, R.Smith - Likely delisted
Others untried.
So to rise back up the latter I think we really need at least a few more AFL quality mids, and probably 4-5 AFL quality forwards. That relies on English, Boyd and Schache all becoming clear best 22 players as well, so we will no doubt need another project forward in a year or two.