The most damage for its shape. Single tooth disk does, in theory, the most damage for a given weight and power input. With the single tooth spinning bar as second.
Any sharp teeth won't be sharp after the first hit.

Damage trough impact. Shock mounting the electronics and drives is very very important.

Hardox will bend first, and then whole panels will be ripped off as the welds start to fail. Fracturing isn't in the books at the moment.

Thicknes of armor. If the shape and fastening are good, thickness adds to the protection.

Lasercutting does affect a few tenths of a mm on the edge of the material.
Not something i'm worried about. Welding affects everything a lot more, even with the right tools and rods.
But yes, waterjetting does the job better in that respect.