That’s really helpful thank youThis might help if you zoom in on some of the basic pics: https://si.shimano.com/pdfs/si/SI-6JJRD-000-ENG.pdf
Ok so I’ve had a play. It seems to me that notch on the hanger that the screw needs to meet up against is in the wrong place?the small screw that fine tunes the gearing is in the wrong position needs turning round to behind the mech. Not in front.
I happen to have a near identical mech and seems to be the same.has the mech been taken apart and put back together wrongly?? try anther mech?