Marion here - I am a newbie to this group but I have cared for my horses for a long time. What is working for my herd is that my farrier works on their feet to match the conformation/biomechanics of the animal. Especially since no 2 horses have the same type of feet.
I have one mare that is suspected PPID, the rest are healthy. I have Arabians and Half Arabians. Another one of my mares has a genetic issue with her front feet and requires balancing every trim.
What helps is that they get trimmed every 6 weeks. Their feet are guaged and matched up to their confirmation. Once they are balanced, they are real easy to keep that way. Once they get off of balance, it is harder but not impossible.
I have heard of the barefooter movement and while in theory, the logic kind of makes sense, but in reality does not really take the biomechanics into account. There is another movement out of California trimming with portable grinders. This one makes me nervous myself. Having short toes on a horse who's confirmation doesn't support it does not make sense and you have a lame horse. For some, an underslung heal could be genetic but with the right care, this can be corrected too.
The more we can learn about the foot and its function, the better we are at taking care of them. I have had my horses for 28 years and though I know a lot, I am in no means an expert. I think you are going in the right direction though. Balanced trims to the structure of your horse, will stear you right everytime. The foot will tell you what needs to happen once you know what to look for.