This is how I managed to give unique faces for created player.
First you have to make the game belive that its an in built player, you can do this by changing the value of the 227th byte to zero(currently its 88 hex). Now with the bat assigner change your face id to the same as the player id.
Then add the following line in that xml file
HTML:
<player medhairstyles="bald" lowhairstyles="bald" location="0000004" name="M. Dufty" skin="1" hattype="none" glasses="false" zinc="false" wristbands="false" towel="false" />
Finally run the game, it will crash by saying a .big file name, note that name and then import your face into that big file.