Pues eso lo respondieron hace mucho: tu escoges a cual de ellos se le asigna los atributos.
"With most replacements, you are either changing one-for-one or you are replacing a group of characters with a single game piece. In those scenarios, this transfer is simple to understand. But what happens when one game piece becomes many?
The answer is that the active player can choose how these game effects get distributed among the replacement characters. Let’s say that Avengers Prime began the game on my force and it was assigned the Avengers: Heroic Age ATA. When I use Split, I now have 3 characters on the map that could all qualify for this ATA. At this point, I need to choose which one of the three can use the ATA."
El articulo completo lo encuentras aqui: http://heroclix.com/heroclix/the-many/#axzz25NFqEOmE