A Viking wore long hair as a dare to his opponent. NFL players also wear long hair, apparently to look bad-ass. That long hair is a handle for the enemy to grab, as soldiers have known from the beginning of soldiering.
You see 'glyphs of an army marching to war with long beards. You see hieroglyphs showing the enemy grab the beard and slit the throats of the bearded ones. You see later hieroglyphs showing clean-shaven soldiers marching to war.
Vikings, as I said above, wore that long braid stuck in their belt as a dare and a taunt. Inasmuch as their success flowed largely from their sheer aspect and the fright that it put in their enemies, it was all part of the package. But in the NFL, nobody's scared because your hair covers your name tag. I'd like to see MORE hair-pulling, myself. The ultimate warrior would wear his hair SHORT. Anything else tells me the guy cares more about the cameras than about winning. If you wanna wear the dreads, brah, do it like Jamaal Charles does.
A rule against horsecollar tackles? Nonsense. If you don't want your guys to be horsecollared, modify the equipment they wear. Surely you could build shoulder pads that don't come with handles at the back of the neck, for Pete's sake. Horsecollar tackles and rules against them are an equipment failure. As we say in Colorado, "There's no such thing as bad weather - just bad equipment."