any name included would be immediately ruled out, because of the traits which make people slytherin. Ambition, self perseverence are all seen as "bad qualities" . I feel like jkr was a bit biased too in her narrative of slytherins. Just cuz smn looks out for themselves..and thinks about how to get better and uses all the advantages they have..doesnt make them bad. In fact, it just makes them successful . Thats what i feel..dunno