It always depends on what your hair used to look like. If the guy had teenage brad pitt hair when he was younger then he might have lost some density and hair.
Given the current pictures I cant see how you say this guy is anything but a norwood 1. If he has lost hair he is still at the Norwood 1 level, but even the norwood scale doesnt really account for loss of hair density.
Losing density of your hair thickness can have a big impact but might be Norwood 1 on the scale