Both Philippe Clement and Nils Koppen knew they would have quite the job in the transfer market when they joined Rangers. Perhaps a visibly frustrated Philippe Clement wasn’t quite so aware of the medical emergency going on inside the club, but it didn’t take a genius to assess big changes were on the horizon no matter what happened this season. With £21m spent last summer, and the League Cup the only return on that figure to date, Rangers are facing the prospect of similar or even greater investment if they’re serious about keeping touch with Old Firm rivals Celtic his summer. Given it will b…