You should only create one player profile per player and attach the player to the squads they will be available for selection for.
You can attach a player to more than one team by going to your WCP > Team Information > Players and coaches > Select the edit icon next to the player >tick the boxes of the selection squads you wish the player to become available for.
The player will then be available for selection for the selected teams.
If you have created more than one player profile for the one player, you should not delete any profiles as this may remove statistics, and cause holes in your database. Contact Pitchero at firstname.lastname@example.org if you need any help.