One more scenario that can lead to overlap.
You can have two defeated opponents that share the same space and one that is replaced first is still shown in the foreground while the one that was defeated last is put in the alternate composite.
I had this happen.
In that case, if the last defeated one uses the finale, it would overlap with the replaced opponent in the foreground.
Ideally, if the finale is used, then the opponent in the foreground should be hidden, if at the same position.