I'm not a blacksmith or farrier, and I have a generalized idea about "hoof angles". It is my understanding that some people (blacksmith/farriers, included) subscribe to the idea that all horses of "x" breed get "y" angle, whereas others subscribe to the idea that each horse gets their proper "angles" by a careful inspection/review of their conformation (especially where their cannon/fetlock/pastern come together).
I have a horse who had a highly recommended farrier literally chop straight across the bottom of her foot - took her heels down super low. Before she was due for another trim (and could even get one, as he'd essentially made her flat-footed with no hoof growth left to "correct"), the shape of her foot had drastically changed. Her toes shot straight out (whereas before her toes grew more perpendicular to the ground), and her heels were basically non-existent.
Needless to say, we immediately contacted another blacksmith, who has been diligently working on my horse to get her heels back "up". We'll make some progress during the warmer months (when she is shod and isn't able to wear down her heel as much), then she drops back down within a month of pulling her shoes :/ It is looking like our only option is to keep her shod all winter, at least until she really develops a heel again. I don't like shoes in the winter around here, as we get lots of snow, ice, and then mud :/ Which poses a host of other problems.
I completely trust our current blacksmith, I just want to learn more about hoof angles myself. I know of a breeder who uses the guy who "whacked" my horse's feet to nothing, and they don't have a problem with the guy and the angles - they just tell him what to do and he does it the way they say to. I feel like, for my horse's sake (and the sake of those in my keep), I should know what (specifically) to say if I see a problem occuring. Not that I want to be a blacksmith/farrier... just, a basic, sound knowledge would be helpful. I don't want to be the person who tells the specialist how to do their job - I just want to be more prepared to recognize a poor job before it gets too far gone.