Mathematically, both can still win in points. They can even finish with the same total points at the end. The minimum for Schumacher to win on points is if he finishes ahead of Alonso in the three races. He doesn't even need to be on the podium. But I guess nothing is absolutely predictable.
We can't take Schumi's 2005 results because the car wasn't as good. I suppose we can take Alonso's 05 results. But Schumi's performance is a wildcard.