You're not going to change my mind on Denethor (unless Carl F. Hostetter's "The Nature of Middle-earth", due out this year, provides startling new insights).
I certainly do not consider Denethor weak. But I do in parts consider him strong for the wrong reasons. And that for at least one reason.
(I don't know how many people realize that Denethor, as per Appendix B, is actually two years older than Aragorn.)
Also as per Appendix B, between 2957 and 2980 TA Aragorn in the guise of "Thorongil" "... serves in disguise both Thengel of Rohan [Théoden's father] and Ecthelion II of Gondor [Denethor II's father]. As per Appendix A "Thonongil's" last exploit was a daring and successful raid on Umbar. Never returning to Gondor after that raid. Denethor, the crown prince, may have been good, even very good. But he suddenly found himself (having started to perhaps become arrogant of his capabilities) totally overshadowed by what was basically a mercenary of unknown origin. And Appendix A is quite clear about Ecthelion II listening very carefully to "Thorongil's" counsels. This being set back in his own father's esteem by a stranger in a time of beginning arrogance might have gnawed at Denethor to the end of his life (and never mind if and when he recognized that this scruffy northern Ranger Aragorn was that Thorongil of way back when).
I certainly do not consider Denethor weak. But I do in parts consider him strong for the wrong reasons. And that for at least one reason.
(I don't know how many people realize that Denethor, as per Appendix B, is actually two years older than Aragorn.)
Also as per Appendix B, between 2957 and 2980 TA Aragorn in the guise of "Thorongil" "... serves in disguise both Thengel of Rohan [Théoden's father] and Ecthelion II of Gondor [Denethor II's father]. As per Appendix A "Thonongil's" last exploit was a daring and successful raid on Umbar. Never returning to Gondor after that raid. Denethor, the crown prince, may have been good, even very good. But he suddenly found himself (having started to perhaps become arrogant of his capabilities) totally overshadowed by what was basically a mercenary of unknown origin. And Appendix A is quite clear about Ecthelion II listening very carefully to "Thorongil's" counsels. This being set back in his own father's esteem by a stranger in a time of beginning arrogance might have gnawed at Denethor to the end of his life (and never mind if and when he recognized that this scruffy northern Ranger Aragorn was that Thorongil of way back when).
To a degree, perhaps. But I think Sauron was able to see from early on in what ways he might delude Denethor. So I have far less confidence in Denethor being able to discern falsehood from fact. And delusion can be a very powerful weapon.