tallyho!
Following a strict mediterranean diet...
But the original OP said he was concerned that the horse had base narrow hooves ... which is quite evident from the pictures ... im simply saying if the break over was bought back at the toe to where it should be, not only would the hoof grow down to where it should be but because that was then not influencing the rest of the hoof the sole and white line would no longer be stretched and the quarters would be allowed to move out to where they should be. this has nothing to do with aesthetics ... but everything to do with how the horse moves and how the hoof functions ... simple logic.
I can see where you're coming from and I have to trim my naturally narrow hoofed horse this way or else we get problems at the toe.