I sympathise ! I'm no expert - so my approach was a bit experimental and involved using a spray bottle to create a mist on the windscreen. That way you can 'see' just how far the wipers trace. (and you can make subtle adjustments in situ to the angle between linkages to hopefully improve things).
Suggestions:
Obvious - but unplug the wiper motor before loosening/tightening any of the linkages. The wipers will always try to 'park' and nearly destroyed my hopes of ever playing the piano
1/ Adjust the linkage held by the nut on the motor spindle. This gets the wipers to 'park' properly at maximum travel - . (seem to remember the motor 'crank' and drivers wiper linkage were in line). Tighten.
2/ Then you can adjust the angle of the other linkage held by the second nut. (Which I think is where you are at). Use the mist bottle to see the result and adjust the angle and repeat as necessary. A small change in the angle of this linkage will change the angle swept by the passenger wiper by a larger amount. You should be able to get that passenger wiper to do more than the 45deg you are seeing now. It's a bit of a fiddle and you won't get it right first time.
Anyway that's my 2 cents. There may be someone out there who has a better answer to all this (the worksop manuals I have seen aren't that helpful)