Precision weapons will always require more skill by definition, because you need to be more precise. At least, more gun skill. That said there are different sets of skills and different levels of those skills required to use either shotgun or sniper to their potential. You can't rate snipers with the same standards you rate shotgunners, and vice versa. That said, it will be hard for a pure sniper to challenge the besy shotgunners with a shotgun, but it will be much harder for a pure shotgunner to pick up a sniper and challenge the best snipers. That is just how it is.