It will probably make it without rawhide depending on the design,, depending on how far you draw it etc, etc, etc,,
I think it is worth the investment in time to rawhide back,, but thats just me,, some say it does not do much,, but for me mentally it does,, starting with 4 inches of reflex, the bow is gonna be a little more stressed than normal anyway,, right,,?? whats your target weight and draw,, and width of bow,, ?
it looks like you have a knot right on the edge of the limb too,,rawhide would help that too