Very good post +rep
I personally agree with what your saying (i think hashi is strongest) but i also see the hiruzen side of the argument, databook provides best evidence for hiruzen argument. Kishi says it himself, in databook AND in manga. So its tough to argue with that, but i believe that kishi really meant for hiruzen to be strongest hokage at the time, and what iruka said at the time kishi meant as a manga fact, but as the story has gone along things change and like you said it is now an incorrect comment from iruka.
I'm with you 100%. But the fact is the wars will never end because some things can never be proven and others can never be disproven.