Is there a correct anchor point is the same as asking which bow is best. Correct is what is comfortable to you, and can be repeated the same every time. Having more than one point of reference is always better. I shoot with the string touching my nose, and the index finger knuckle closest to my hand behind the ear. I had a third reference point with the fletch in the corner of my mouth until I started shooting cock vane up, which changed the angle of the hen vanes and made it feel wrong.

The most important part is the repeatability.