Sprite sheet and animation slice doubt

I'm working on a prototype using the sprite sheet that I attached here , the main problem that I'm facing is regarding the slice.

At the beginning I was slicing by fixed width and height (64 x 64) and pivot in the center. But I've been watching some videos that always uses slice automatic and pivot bottom , I prefer this approach mainly because I can know that the bottom won't have empty image without any pixel of the character.

The problem that I faced is with the attack routine , with the first solution (slice fixed) it was working as expected the attack animation was working smoothly , but with the second solution the problem is that the guy doesn't seem to attack , it seems the weapon is fixed and he moves as he steps back.

I'm not sure how to solve that issue , maybe using (add property / transform) on the animation to fix the position ?

Which is the correct slice that should be applied ? And what to do with those odd sprite animation that happens due to using the slice automatic ?

Thanks !