Barnes/MetuBagley/Holmes is a paint-clogging nightmare (Metu less than Bagley since they can make him a viable stretch 4, but he still camps too close to the basket too often). Harkless through no merit of his own allows Barnes, Holmes, and Fox to be better utilized just by being there.
The things this team needs now is
A. A coach
B. A souped up, starter level Harkless, AKA another combo forward in the Barnes mold such as a Miles Bridges or OG Anunoby type.
C. Fox to regain form and the other two of the guard trio to keep developing.