The thing to think about is this... When we reach the playoffs, we should have two pretty healthy and fresh RB's, unlike some of these other teams who ride their RB all season (EX: Seattle)
actually alexander IS fresh, coming back from that injury, his 201 yards mon night showed that, albeit against GB. I do think denver is going to tear them a new one this week, however...
but i do agree, the 2 back system should keep out guys fresher late into the season