I do agree with your logic however in the playoffs I stick with the horse you rode to get there. It is tough but if it were me I would roll with RG3.
Best of luck
13 team Roto keeper league 12 F, 6D, 2G, G,A,+/-, PIMS, Hits, TOI(D), GAA, SV%, (Forwards are forwards, no distinction between L,R,C)
F) Ovechkin, Stamkos, Kane, Ryan, Clarkson, Couture, Ribeiro, Moulson, Van Riemsdyk, Orr, B. Morrow, R.Malone
D) S. Weber, Phaneuf, Subban, Shattenkirk, J. Johnson, Hedman
G) Rask, Khudobin