Alright, well, then take'em out of their respective sports.
How many NFL players have been olympians, successful in other sports, and even held world records compared to Rugby players? (I'd love it if someone would do the research on this, but I can think of several off the top of my head.)
I'm pretty sure it isn't even close.
Why? Because the NFL takes the strongest, fastest, most explosive, and most "elite" athletes at specific abilities and puts'em on a team together.
Rugby players may need more "overall athleticism" than many NFL players, but really, being good at everything usually means you're not great at anything.
Running a marathon isn't going to help a world-class weight lifter, sumo wrestler, or an NFL lineman. A great 40 time won't usually help a pitcher, a javelin thrower, or an NFL quarterback. Michael Phelps would probably suck at Rugby, but he sure as hell is an elite athlete.
That's what's so great about football. You field a team of elite, world-class athletes who cover the whole spectrum of athletic abilities and then work together to put all those varying, but elite, abilities into a cohesive unit.
[ Edited by mug0mug on Feb 7, 2010 at 2:28 PM ]