I thought that since wb,wc and wlight all come from the same W+jets sample, the uncertainty on the W+jets rate affects wb,wc, and wlight all the same and is fully correlated across them. This is what I have as 'wj_rate', a fully correlated uncertainty on the W+Jets xsection. Additionally, on top of the overall uncertainty on W+Jets xsection there were two uncorrelated uncertainties on the b-flavor and c-flavor selection 'wb_rate', 'wc_rate'. This is what I remember Victor telling me we did last time. 

The way Marino coded it, each wb,wc,and wlight have an uncorrelated uncertainty on the rate, and there is no information about how they all come from the same W+Jets sample.