Florida lead the league in shots generated off of board battles won. By definition they have the most "grit" in that category. Add player like Gudas, Tkachuk, Bennett and Lomberg and you've got a good group of pricks that will throw the hits. I think they're in the discussion for most gritty, especially with how Maurice's coaching style compliments those specific players who like to grind out their chances.
Softest has to be Carolina. Maybe the Jets too but honestly Carolina is a butter team. They'll need to play impeccable defense to be successful this year, thankfully for them they're capable of it.