Is it not possible to maintain a 'strong' grip while also being relaxed? I was taught that one can 'localize' a strong grip while maintaining relaxation throughout the rest of one's body. In other words, I'm not sure that a strong grip and a relaxed body are mutually exclusive.
I suppose you can but it has little function, why neutralize one of your weapons? If I wee fighting, as opposed to training, I'd have the guy's balance broken and I'd be letting go and striking all in one movement. Or i would have taken him down at the moment of contact... neither of which requires a strong grip. One should grab ones partner the same way you hold a sword. I hope you don't white knuckle your sword...