To some extent, additional ADT and additional radiation dose are probably interchangeable, but there are still a lot of unknowns.
In the following retrospective study, each month of additional ADT decreased the risk of salvage radiation failure by 10%. Going up to 2 years decreased the risk of failure by 9.8 fold.
www.redjournal.org/article/S0360-3016(13)01075-4/fulltextIf you haven't seen it, the following article makes the case for higher dose:
/pcnrv.blogspot.com/2016/11/dose-escalation-for-salvage-radiation.htmlAs you said, it's water under the bridge for you at this point, but I'm glad you are asking all the right questions. That's the most any of us can do.