I'm right/right, but my right eye was damaged by a rock thrown from a lawn mower when I was 19. My vision was excellent after the damage healed, but began to deteriorate with time as scar tissue built up. By 5 years ago I was functionally blind in that eye, and wouldn't have been able to drive without my left eye. My shooting suffered. I was barely confident enough to hunt. Eye surgery technology finally advanced to the point that my eye became repairable. Four years ago I had it done. My shooting immediately improved and my confidence, along with it.

Eye dominance is like "handedness" in that if varies greatly between people. Some people are ambidextrous and can use either hand equally. Eyes can be like that too, and everything in between. I tried shooting left-handed with an ambidextrous bow I had, but it was difficult, and my confidence was no better, even though I had been relying on my left eye for years.

Am right handed, but left eye dominant. Same as your friend, I shoot my guns left handed. I shoot all my trad bows right handed, and do so very proficiently.

No issue for me.

Right eye dominant, shot right handed for 35 years.  Began switching due to TP and tensing of my right hand in 2013.  I shoot lefty only now except for right strength training.  If you look at the arrow and use it as a sighting reference in your conscious awareness, you might need to squint or close the dominant eye.  I shoot with arrow in secondary-peripheral vision and have consistency now in shooting lefty.  Many good bowhunters shoot off non-dominate eye.  I like that I can shoot both ways...