RE: is it hard to shoot a very fast bow
If I couldn't hit a six inch square at a measured 60 yards and I had a pin for it I would be PO'd.
Now if your guessing at the yardarge and the bow isn't set up for it that is a different story.
I think it really depends on what your skill level is and what your willing to accept. I know guys that are happy if they can hit an eight inch pie plate at 20 yards. To each his own I guess.
I'm not saying your not correct on your assumption, but just because YOU can't do it don't think no one else can either. I have seen some pretty amazing things done with a bow and I don't go to a lot of target shoots. I have seen guys shooting traditional equipment with no sights that can shoot better than me. Sort of humbling, even though I didn't think I was that great to begin with.
Some people are just naturally good at this.
By the way the 10 ring on a 90 meter (98 yards) FITA target is around 4 inches.
Paul