No, those shackle mounts would be stronger than anything you can put on them. They are a "T" shape and instered from the back and then welded on both sides.
As to why they are thinner than the rear...I don't really know. I wish they were thicker. I think it would "look" better, but it wouldn't make them any stronger.
BTW, if you are that stuck, my guess the bolts holding on the bumper would fail before the shackle tabs.