Funny you should mention that. I just started Return of the King. Yes, I have had the thought of his reasoning on the use of power is very much like Boromir’s (and Sarumon’s too), though he (Boromir) expressed remorse and redeemed himself.
Enjoy the book. The idea of a good King belongs in fantasy, Aragorn is a good King in the books but look at the rest of the monarchs and strong men (the boss in hobbiton for example) and you we note that JRRT really did not much care for monarchs all that much in all likelihood. While we here at free REPUBLIC seem to be split on the issue I guess a world war and 10 million or so dead soldiers does give a person perspective on strong man leaders.
If you want to see a good series on the war, that shaped JRRT’s Middle earth I recommend “The Great War” on youtube.