I agree with your assessment on Shaq vs. Duncan, they have a healthy peak vs. longevity between the two, with Shaq better at the peak, and Duncan being able to sustain his excellence quite a bit longer.
I don't think Shaq > Duncan, because Shaq requires a very specific team around him to be effective (bunch of shooters, and elite wing, rebounding/defensive PF next to him, little leadership responsibilities), and Duncan is most definitely easier to build around and much more easier to sustain than a prima dona Shaq, but Shaq does have an incredible peak.
And it's not just SOME advanced stats showing Duncan > Kobe, almost all of them do. Also, could you quote the GMs and peers picking Kobe over Duncan? All NBA voters is tough to apply, because they play different positions, and HoF, as we all learned through the years, are mostly a bunch of old senile guys who like to live in past glory, and are generally horrible at picking players, but I would like to see the list as well.
Interestingly, in MVP award shares, Duncan leads Kobe despite less years and playing in San Antonio vs. the LA limelight, so I am not exactly sure if the media types, as clueless as they are, picked Kobe over Duncan.
Speaking of peaks, when was Kobe's BTW? I define Shaq's as 99 to 03, Duncan's as 98 to 07, but am having trouble pinpointing Kobe's.
I think you misread me, I think we are on the same boat where I think Shaq > Duncan in their absolute primes (few people > Shaq, but 91 to 93 Jordan is there, if not > Shaq), but Duncan likely beats Shaq in terms of being a better player, maybe by a hair, with defense being the strongest, but not only, reason.
I want Tim as a big over Shaq over the course of their careers if I were to start a team, just easier to build around, actually listens, gives his all on the court, no drama, better defensively, better range, equal passers, better leader, though not as dominant an offense force as Shaq.