I agree Baranczyk makes it a point worth debating. Sanu had a good game. But in part that is by design as the Packers would rather Sanu catch all the balls rather than Jones.
Average value is a very rough measure of player success. Its partially dependent on stats specific to a position, but also takes into account things like postseason recognition. Its not the end all of the argument. But Sanu has been underused compared to the other two. If he is a talent on par with them, his teams haven't figured it out yet.