I used to spend about as much time working on wind flags as I did reloading. I had spinners and ribbons that would tell a story that I understood. I have placed as many as 10 flags between me and the target. Wind conditions are not the same over 300 or 400 yards. The wind can stop dead at 200 yards and blow 15mph at the target. Or do just about anything really. In bench rest rifle we shoot wind conditions. That means you shoot on a condition you are reading from your own personal flags and you shoot all 5 shots on the same condition, if possible.
Without wind flags, there is always luck.