Hi chaps,
Thank you, glad you like them.
Yes, the 90 degree rule is not an exact science as there would be times when yards would square up but ships crews would look to avoid it. That said, models are a compromise in that the masts and yards are modelled that way for obvious reasons and twiddling them on the hull simply leaves the fighting tops at angles so, rather than cut the yards off and angle them accordingly, you let the eye do some imagining.