Hello Jim,
It's called "shared decision making", which means they are supposed to give you the information you need to make the decision. That might (I would argue, should) include listening to you to understand what your priorities, fears, etc are, and talking around how each treatment would impact those. However, I'm only too well aware that many men feel the shared decision making wasn't very shared.
At your young age, one concern I would have is that you are looking for a long time in remission. That might mean having to have more than one treatment during your life, so you might not want to start with one which is difficult to followup if the cancer comes back. That means I would consider leaving radiotherapy as an option you might take later rather than now. That's not a suggestion I often make, except in younger patients who are more likely to need a second treatment later in life. As a T2a G3+4, you might also be eligible for a focal therapy, but that's something they won't suggest unless they offer that treatment - you would need referring to a centre which does to get an opinion on it.
Then there are things like how important is sexual function to you, and for each of the treatments, how likely are they going to be preserving it. For prostatectomy, being T2a, I guess you will have at least one side nerves spared, but the other side will depend on the location of the tumor. However, even with both sets of nerves spared, erectile function isn't always preserved and is usually impacted to at least some extent. There's also urinary continence, and it's worth asking if the tumor is near the apex (bottom) of the prostate, where it can have more impact on continence after prostatectomy.