Not sure about Monfries he is pretty inconsistent, maybe better to get someone like Christensen.
Saad is a proven goalsneak and mature age but will he get into the StKilda forward line with Milne/Schneider in there already?
Backline looks a little bit weak, maybe spend a bit less on your rucks and upgrade someone there.
My current lineup, fairly reliant on GWS rookies atm but may change those according to round 1 teams:
Not too bad but like you said, pretty reliant on GWS rookies making you some cash!
Idea isnt flawed but id look at swapping some of them for rookies at other sides to mix it up because the GWS players will most likely get rotated alot!
Also i think Christensen may be injured at the moment so double check that!