What would I do? I'd do as much reading up as I could, with my eyes open to the source of the articles I was reading, so that I had a basic understanding of low heels. I'd then ask my farrier if he would explain why the heels were so low, what problems were associated with low heels & what problems would be involved with trying to alter this if he thought it was desirable or possible to do so. If I was really worried I'd get foot balance x-rays done, it may be that his heels are low but his foot balance is fine & trying to increase the heel height would actually unbalance the foot & cause problems.
Of course if you don't trust your farrier enough to ask the question & expect an honest professional reply then that's a completely different issue & I'd be looking for a new farrier.
Low heels are not always bad. I have two laminitics whose heels are kept low to help with pedal bone alignment, one in particular looks very low on his heel (his whole foot shape emphasises it) but he's happy that way & if the heel gets a little too high he is less comfortable. I've had detailed explanations from my excellent farrier, read up on it, seen his x-rays & also seen his response to this trim & I'm happy even if his feet may look odd to someone who doesn't know what we're dealing with.
PS when talking with farriers I'd make it very clear I'm asking, not telling them their job!
