That's incredible. However, I'm not sure that sort of rapid firing approach would give much range. An archer using a longbow just wouldn't be able to move like that.
It's possible to shoot really fast and be very mobile with a recurve bow, that's what they're meant for, but not all types of archery work the same way. You can still shoot a lot of arrows relatively quickly with a longbow, but the range is what they're especially good for, and if you're shooting at a large group of men/horses, you don't need precise aim.