In fantasy football it is very hard to trade Defense for Offense even if the their values are the same or even better for that matter. The only way to get better on offense is to draft offensive players (sounds like you will have the 1st pick in the draft next year) and to trade offensive players for offensive players.
Now if you were stacked on offense and you wanted to shore up your defense you would be able to get a really good return on your offensive players.

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Derek Reese - Future Hall of Famer
Studs N Duds - Sunday's

12 Team NHL Salary Cap Dynasty
H2H, Salary Cap 82mil, Player actual salaries
G,A,PTS,GWG,PIM,SOG,STP,HT,BL,+/-,W,GAA,SV,SO
Starters: 12 Forwards, 6 Defense, 2 Goalies

F - Stamkos, Perry, E.Staal, Voracek, J.Staal, Simmonds, Ott, Downie, J.Jokinen, Eller, Nielson, Prust
D - Martin, Faulk, Brodie, Ellerby, M.Weber, Stone
G - Bobrovsky, Halak
Bench - Brunner, Brodie, Strachan, Khudobin, Lindback, Neuvirth, Ramo

Prospects - Calvert, Forsberg, Etem, Namestinikov, Kreider, Cundari