Well, I am not an oncologist, but I am a patient looking at biochemical relapse after surgery 4 years out. I know I will need about 40 treatments buy they haven't told me yet about how long the duration of hormones would be. From what I've heard, they are NOT fun nor are they good for you, but they do tamp down the disease.
However, it DOES seem like a long time to be on hormones in your case. I could see continuing for maybe 3-6 months after radiation, but more than that?? It seems like overkill to me at this point and I would definitely get a second - and even a third - opinion. There is no "one size fits all" for this disease so you may have other factors that are being considered. If two other oncologist agree with your first one, well that's pretty much it. But I really think you will get a wide diversion of opinions here. Best of luck and please let us all know what you decide.
AL