I don't get this issue with the full backs. We have 3 left backs including 2 full internationals and an England under 21 international (ok Rose might leave but I hope not). Two of those play good attacking wing back roles and Davies is a good solid left back. At right back we also have 3 - a young full Argentine international who clearly has convinced Poch that he is good enough, the Ivory Coast captain and a good young England under 20 international. Two of these also play in the attacking wing back role and (hopefully) Foyth will be a solid right back.
Personally I like Aurier - if he stays I hope he gets a run in the team to prove that his early potential can be proved. If not then I seem to recall the oft repeated mantra 'give the youngsters a chance'.
The strength we now have is in depth of squad and quality in that depth. If we keep Eriksen so much the better. The only one position where we struggle with depth is a true Centre Forward - but Kane isn't a true centre forward and whoever we had bought in would have required a shift in tactics to replace him in games. So why not stick with the mix of Son, Moura, Alli that we used successfully last season .
A good transfer window that has increased our squad depth and quality in my view.