It's close between Schaub and Cassell. I give the slight edge to Cassell based on (as you've said) NO's defense and the shootout potential.
(0.5 PPR, 12-team league)
QB: Vick, RG3
RB: McFadden, Matthews, K. Smith, R. Williams, M. Goodson
WR: Nicks, S. Smith, Britt, LaFell
TE: Hernandez, Pitta
DEF: Spot start (Cin in wk4)