Cooper does not currently have the experience of playing in either the Championship or the Premiership, but he has the potential, and is on a journey towards those goals.
He currently is not as experienced as Pickford, for obvious reasons, but we do not know whether he may be able to match or exceed Pickford's ability when he gets here.
Cooper has solid foundations, but he still has to prove himself in the higher leagues. There is no doubt about his ability at this stage of his career, but he is on a journey and will have to prove himself to become a Premiership keeper, and maybe he will be selected for further development in the England environment, maybe.
All ifs and buts at this stage of his career, but we all think that he has the potential, and it is whether that comes to fruition, through his career development, in order for his potential to be fulfilled.