This is clearly the preferable situation for Federer, if Murray gets to nr2 Federer is guaranteed to not play Nadal until the RG final. Also he can get Murray in SF and Djokovic in the final, ideal situation to have a shot at RG title, but this is a long shot ofcourse.
Thing is if Federer is nr2 and Murray ends up in Djokovic's half it is not all that good for Federer, he gets to play Nadal in yet another SF and Murray might just beat Djokovic just to lose in straights to Nadal in the final.
Indeed. If Murray can get to #2 and Federer is drawn in Murray's half, then conceivably Federer can beat Murray in the SF (or Murray loses to a mug before the SF) while Djokovic takes out Nadal in an epic 9 hour semifinal leaving Djokovic toast before the finals.
Obviously this is not going to happen, but it's a nice thought.