Drop penny for mike williams?

Hey fellas, im short on wr(nuke, sanders and djax) and great at rb(cook, carson, karama, lindsay, singletary, mattison and penny). Its a 0.5ppr, i was considering picking up a WR and mike williams just hit the waivers, the options are him, davante parker and kenny stills.
Should i drop one of my rbs for any of these receivers?