Baseline settings for recurve sight

What is a good baseline setting for a recurve sight? My coach noticed that I had my sight set way too far to the left. He told me that the sightpin should be roughly in line with the arrow in the bow.

My sightpin was pretty far to the left, I think easily 4 or 5 cm off to the left of the arrow line.

If I move the sight to be more in line with the arrow I'm hitting left from where I'm aiming. I know my arrows are slightly stiff but they shouldn't be so stiff to throw them that far left. Could this be a form issue? To add to this, I did check my eye dominance and this seems OK, completely right eye dominant shooting with the bow in my left hand.

What could cause this, and is my coach correct in the baseline setting for the sightpin?