Kate Aurthur editorBianca A. Santos and Cedric Sanders have been added as recurring cast members on Season 18 of ABC’s “Grey’s Anatomy,” playing a married couple in a dire medical situation — as if there is any other kind at Grey Sloan Memorial these days.Sanders is playing Simon Clark, who is desribed thusly: “A devoted husband/ father-to-be, Simon is depleted from a long-term battle with a serious illness.