Id keep both Ake AND Stones simply because they are unsellable pieces of glass lol. Might as well keep until contract runs down and give 1 year extensions if they happen to keep some form of fitness.
Otherwise I like the idea of Doyle and Ake as left footed CBs.
Only thing id change is swap Lewis for another RB, who is more like a CB. That way the RB you chose could be like Livramento, with the other a more defensive option.
Lewis for me simply wont cut it as the kind of fullback I want. I think Pep has to mold him into a 6/8 hybrid and just let him learn that. Even still, he would just be a backup, but a high energy one.
Edit: As an aside, is Doyle doing well on loan?