I know what ur talking about - sometimes i think 'how come my $17k SG is still doing ok, yet my $100k SG only performs just that little bit better?
Over the y ears ive realised a few things. As some other posters have suggested, experience is one. Stamina is also another - likewise with a backup coming off the bench with high stamina, it may appear that he is blitzing, but its just a stamina thing.
Also I think that whilst individually that player may seem to be doing better, its all those unseen things that the better player will provide to the team, the untangabile things like, better offensive flow, freeing up other players for shots, being the link guy in a string of passes. Just cause he doesn't get the stat doesn't mean he isnt providing for the team.
so i agree it certainly may appear that way, but logically, there is always something behind it. There is always a reason for that apparent 'betterness'.