I like Coleman quite a bit as a project but the reality is he's hardly ready to contribute right now past special teams. Moats imo has shown more pass rush ability so far and I'd be a bit surprised to see him cut for Coleman. Moats also has all that college experience lining up with his hand in the dirt, which we love to do with our OLBs.
As for the move to the inside, I thought it made sense before Morrison was signed. Who was the first ILB off the bench in case of injury to Barnett or Davis? Torbor? It's easy to see why they gave Wanny a crack at molding Moats into an ILB. But the signing of Morrison should have immediately kicked Arthur back outside.
Just the opinions I've pieced together, could be wrong