Years ago, 1993-94, I was walking to the target butts with a buddy and one of his bows that he made(he is a top end bowyer, and excellent archer).
I was already making excuses about missing as we approached the line. I said things like, " this bow is not tuned yet", or "I never shot this one before", I'm not used to this design..."
My friend had had enough of my excuses and told me that a good archer could shoot anybow. He took the bow from my hand and hit the mark several times, the proceeded to do the same thing with everyone's bow in our little group. Same arrows, different bow, archer making changes as needed.
An American Longbow is a very excellent and easy to shoot bow. Don't make it hard, but above all, don't make an excuse. Its not that hard, Keep it simple, because it is.