, By star players do you mean first team players? Wouldn't consider any of the players bought by Martinez or Koeman star worthy. I wouldn't have even given you Lukaku as a star when he came. He was just a striker too good for WBA, not good enough for Chelsea who was also wanted by West Ham.
Imo the biggest thing about all of these signing is their ridiculous fees. But I'd say like 90% of the players brought in by PL sides are vastly overpriced. Every single side in the league is being taken for foolswhen it comes to transfer fees and wages.