2d polygon colliders make them NOT fit the sprite

I have a code that changes colliders of my sprite at runtime as the animation happens, The only problem is this only works with polygon colliders.

Normally this wouldn't be a problem, but when i want to make a damage radius for my ground smashing attack, I have to use a polygon collider. I figured I would be able to just make a polygon collider that was shaped like the hitbox, but I can't seem to get a polygon collider in the game and edit it. It always adds like 40 vertices and then i have to go in and delete all of them. This is a big pain and will really slow things up when i add more attacks.

So all I want is a way to free edit a polygon collider, is that too much to ask? anyone have any ideas to help?