Eh, Marler's not there while Rodd is, and Pearson and Barbeary are there while Simmonds is absent. The England staff will have some metrics of whose run furthest/had the most contacts and have decided that some players who are lacking in those areas would benefit more from having a week with their club and getting a game in on the weekend rather than staying in camp. As Olyy said, I really wouldn't read too much into this squad. Save your outrage for whichever squad is announced next week.