I'm not too familiar with leagues like you've described, so I'll leave it to you to apply the necessary context around my feedback.
I owned Desharnais for most of last year, and his production was fantastic, even though he was primarily only putting up assists. Pouliot produces in more categories, when he does produce. He was a highly touted talent on draft day that has been slow in developing, but as long as he is where he is in the lineup, the production will be there. He's always at risk of getting shuffled out of the top 6 though, and it will be interesting to see what the lineup looks like when Malone returns from injury. I feel like Desharnais is a safer pick, but Pouliot is a better very short term pick up. Just don't be shy about releasing him if he gets cold again.
12-team H2H Semi Keeper (keep 6)
skater cats (7): G, A, P, +/-, PIM, PPP, GWG
goalie cats (4): W, GAA, SV%, SHO
6 keepers bolded
C(2) - S. Crosby, E. Malkin (W), S. Ott (W)
W(4) - A. Ovechkin, D. Brown, M. Ryder, B. Saad
D(4) - K. Yandle, D. Phaneuf, M. Green, R. Josi
G(2) - MA. Fleury, J. Halak, T. Vokoun, V. Fasth, J. Allen, R. Lehner
IR - E. Karlsson (D)
Next year's draft picks (1-6 are keepers): 7, 8, 9, 10, 11, 11, 12, 13, 14, 14, 17