I've been having problems blocking and parrying, I find that when I press left or right to change my stance that I'm usually pressing left-up or right-up because my thumbs are long and the xbox one controller is small, I've tried training myself to do straight left and right thumb stick pushes but I always in the heat of the moment press in those directions.
I'm suggesting that ubisoft add an option to change the zones like being able to shorten the area that activates the top stance and widen the left and right stances maybe even the down stance for warlords, conquerors and nobushi if the player desire these kind of changes.