Personally I think timing of the block is important. like you need to hit the block key when the thrown item is within 3 feet. This makes more sence. Because if you don't put this in combat then people will just hold there guard key down until there ready to attack making kuni and shuriken and even basic Kenjutsu usless.

Also guardat first  should only work for 1 impact.
So if some one throws 4 shuriken at the same time- a high level shuriken jutsu.
You would need to have an equally high level gaurd to block 4 Impacts with one key stroke.

Welcome to the forum, I hope you enjoy your stay here
I see you play 'Basket' which I assume is basketball
If so;
What NBA team do you support?
What is your height?
What is your position?
Do you play casually or with professional coaching?
How long have you played for?