I think Dotson will end up being pretty good. He has very good speed but is coming off a late a fall ball injury (he missed the last open scrimmage and the BSU game) so he should look better the next time he gets some carries.
I dout Dotson ever does anything significant at UW. McGrew is a better player and is maybe even faster and Gaskin is already much better. If Wellington plays RB, Dotson is selling the couch unless he really wants a UW degree.