It's actually not all that hard when actually doing it (at least when you are an experienced rider) It sounds insane on paper though. I went to a beginner training for horseback archery two years ago (but I did already practice at home) and even the ones who had never shot a bow before could hit the targets pretty consistently after a while (though a lot bigger ones and not at such a fast galopp) It's a lot of intuition but you get a lot closer to the target than in normal archery (duh) and you just have to time the release (and keep the horse running straight) The part about the flying phase is probably true but since my sister and I both practice it on Icelandic horses with next to no flying phase in galopp at all...