Interesting observation...
If I recall correctly, Cutler in 2001 (his breakout year) was either #1 or #2 (posing order) before getting shafted by a less-than-peak Coleman that year. If we want to be ridiculous with conspiracy theories, the IFBB could be protecting their champions by putting the top challengers first in the lineup, so by the time 15 or 16 guys are done with their routines, the first couple of guys are mostly forgotten about. Hmmmmmmmmmmmmmm......... ..
Of course for this to be at all feasible we have to assume that the "judges" are actually scoring the contest fairly and there's no predetermined winner (in which case the posing order would be meaningless). I have a hard time buying that, though...