I am no doctor but I do know a few things about the organized side of medical. Medical science about T treatment is super charged with politics in the medical field so doctors I think don't want to bump heads with the endocrinologist and/or their own boards.
I am 52, I had 325 and gender confused doctor said that's high T.. I Quizzed him thoroughly after hast stupid statement.he made. Before, prior to Obamacare, I got to a real T-center; a practice dedicated to T, with hot chicks giving me a shot one time a week. The doctors knew their shit too and they would have me closer to 500, they were still extremely conservative and take for ever I thought but the end result after a 8 months of testing got it down right.
Today I keep it near 350-500 and I get along pretty good. Wont try to go higher until I loose some more inches in the belly. The belly + older age can complicate things.
Another thing your dad's doctor may not be considering is the irreversible damage of the effects Low T (under 300) has in Arthritis and the deterioration of the joints and cartridge. Family practitioners are just not cool about T-shots I think hate it simply because it confuses them and exposes them to malpractice and board reprimands big time, they would rather see him get his shots from a T-center or anywhere but there.. then come back to them for everything else. . When I used a family/general doctor would give me one shot once a month and just keep my pituitary guessing making my eyes water, net effect I was worse off
Moral of the story, if you are treating low T, go to a T-center if you git the insurance and means to afford it. They run panels all the time, watch out for side effects and stuff like that.
Hope that helps