I prefer Dummett as a centre back, don't think he has the pace or athleticism to play LB like Haidara does.
Ideally for the new season I would want 2 new CB's, Lascelles third choice and Dummett fourth choice (flogging Colo, Taylor and Williamson) but there's no way that'll happen now. If it was to be the case, I'd want the 2 new CB's in now working on a partnership instead of chucking them both in for the Southampton game Think it'll end up being Colo and a new CB as first choice with Dummett and Haidara rotating the left back role.