I looked up this exercise and I noticed that many people have their feet turned outward. This decreases stability and it doesn't strengthen the correct leg muscles required to make that stance strong and rooted. The legs will get stronger but the stance won't have a strong root.There's a lot of surprising stuff once you scratch the surface. For example, the following is WC. For some reason this guy didn't think it was hard enough as it is, so he's wearing a 50# weight vest!
That exercise with the feet turning out strengthens the hamstrings instead of the quadriceps
Is there a reason why the feet are out like that in WC?