Jim.. .I would think that the palmered hackle would give the fly a bit more fatter shape at the forfront which silversides have. Tje creativity of various tyers always amazes me. This winter on a trip to florida.....i found a whole bunch of different fly construction techniques....must admit, I stole from them all.
I noticed you used purple....that I found to be a very popular color while fall fishing in RI this past season...there is a whole clan of folks who swear by purple.
My most successful fly this fall in RI was a 2 inch all whiteshminnow snook fly...go figure??? Not sure how important color is.....but fishing Bay side i have found grey sand eels do far better than the typical chartreaous/olive over white. On cloudy days, even black produces. Then again, "my son", only uses chartreaous and have great success. Maybe if the fish are feeding...it really doesn't matter....it may matter more to me