In my case, 3+4=7, localized and Intermediate risk, my urologist and RO both agreed that a six month course of Eligard should start before my SBRT treatment (True Beam STX). Both, as the OP suggested, wanted the ADT to starve and weaken the tumor cells so they'd be more amenable to radiation. So I had my ADT shot on February 14 2024 (love the irony of a hormone shot on Valentines Day ;-)) and I started radiation in May, with the final 5/5 fraction on May 17.

The specifics of your case may dictate your RO's preferred course of action, and/or that's how they were trained and are most comfortable with that treatment plan. I don't know if there is any reliable research suggesting one approach or the other, but it's worth understanding your RO's thinking. And you may want to consider a second opinion too. If I've learned anything in this journey it's that self-advocacy is a necessity, and that may not always be easy when we're talking to "the experts". Best of luck to you, and warrior on!