AR steels are hardened. That means more wear resistance than mild steel but also means there more prone to breaking vs bending. Its kind of like picking your poison.Do yourself a favour and focus on light weight using high strength materials. Buying something with thick tines made of mild steel is a waste.
I'd rather have 1/4" tines of AR400 than 1/2" thick mild steel.
On the other hand your paying more for AR steel. How do you check to see what parts are actualy AR steel in a grapple? Do you think the whole thing is? Seams kind of un need to me to make the whole thing out of AR steel.