This is an interesting post actually, The players are only separated by 1 skill point, lowest end of 6* and the highest end of 5*, basically for category purposes and for who can see these players for transfers when placed in auctions, but the real difference is only 1 skill point so visually and comparison the difference between these 2 players will be illegible. For transfer purposes the 5* 1 skill point away will be more attractive to managers bidding on the player in auctions while the 6* player will most likely just get 1 bid from a manager above.