So the plan then is...
Trade 1)
Carlton get: Marchbank and pick 15
GWS get: pick 5
Trade 2)
Fremantle get: McCarthy and pick 7
GWS get: pick 3
Trade 3)
Essendon get: picks 3 + 5 + 16
GWS get: picks 1 + 20 + 38 + 2017 2nd rounder (or pick 27 for Hibberd trade - depending on if they want more points this year or next).
Approx even on points.
Having picks 3 + 5 in the draft is essentially picks 3 + 4 as we know even if Brisbane don't bid on Bowes with pick 2 we can bid on him at pick 3 and force GC's hand.
Regarding GWS's position you can see it 2 ways:
1) They're giving a hell of a lot to get pick 1
2) They don't really care about losing those players and now they get pick #1 and insure they get all their academy picks anyway.
I think if Freo gives up pick 3 then they will probably want something extra from GWS, or maybe us, so they can trade it for Brad Hill. Pick 20 or the Hibberd pick?