You don't have to be muscular if you take roids. Look at all the cyclists or runners. It's absolutely possible these guys take minor doses of steroids for regeneration.
You're absolutely right - They might eat regular clean diets of 1500 to 2500 cal a day, train nautilus 2ce a week, and play lots of golf. They're not going to achieve much muscle mass with a light cycle. Rather, they'll just keep themselves a little stronger and a little more durable.
Steroids in golf is the dumbest thing I have ever heard. Thats like a pool/billiards player on sauce. Oh brother.
You have men (many in their 40s, 50s and older) walking for hours for miles in the sun, exerting themselves physically with the long drives, and doing it year round.
That takes its toll. I'm sure many of them have joint, muscle, and bone issues that add up, but if you're going to make tens of thousands (or more!) of dollars playing two days of golf, you're probably going to suck it up and do it.
At the very least, a light HRT cycle is going to make these guys play, feel, and live better as they do the same repetitive stuff.