Well, I went to the website.......not so sure this gentleman is very creditable, sorry. He's got a couple of points, but that's about it.
The proper breakover cannot be achieved by just chopping off the toe or squaring a shoe. There is a lot more to it.
Squaring the hind toes is done as a first step, before surgery, blistering etc, in a case of upward fixation of the patella/ locking stifles. Worked for my horse