I think Dr. Selar would have been a better junior medical assistant than Nurse Ogawa. However, I'm sure the show didn't need the cold logic of a pure Vulcan. T'Pol turned out to be a total mess.
With the benefit of hindsight, Suzie Plakson's history in sitcoms points to comedic acting for her. Perhaps then I could accept a producer rejection of McFadden's suggestion, making Crusher more serious than she was but without turning her into a total character turn-off.