The selection policy is "no", basically. There was talk about "special circumstances" for overseas selection when Fat Steffon was doing his thing in France but nothing came of that; no-one's going to break the selection agreement for a number 8 when we have two good ones duking it out already.
And yes, Simmonds retaining the shirt made no sense to me either. My view is he's changed his carrying approach this season and he looks a bit scared of being held up / hit by a dominant tackle, so he's aiming "down" when he carries and always hits the deck as a result. So he carries a lot and makes yards but it's never more than that - no breaks, no offloads - and while he does make a lot of tackles and has excellent workrate it's not the impact we were hoping for. Meanwhile, Dombrandt was near the top of the table for turnovers won in the 6N despite playing mostly off the bench, runs great lines, has great hands, is a proper lineout option, and is a heavy carrier on top of that.