I'm not sure that modern rugby players are anything like the 'tough guy in the pub' ..... an average Second Row forward in rugby is about 6'6" or taller, and these guys are about 19 stone. Some of those Polynesian players are every bit a physical match for NFL players (ie all fantastic athletes).

I met Bryan Habana (the tiny guy on the wing for South Africa that you see as a bit of a weedy guy on TV) and he was FREAKING HUGE in real life. 'Skinny' Joe Rocokoko is 6'3", 16 stone and does the 100 metres in a near-Olympic qualifying time.

I did notice that the NFL players in the clips were not really tacking, they were using themselves as missiles, and really trusting their armour would protect them ..... I suppose that's an inevitable outcome of this making the 2 sports diverge?