That's the essence of your argument: 4th quarter stats>all.
Um, guards who are the best freethrow shooters on their team will typically have good 4th quarters in close games their team won because a lot of their scoring comes from intentional fouls. By whittling down a comparison between a big and a perimeter player in that regard is disingenuous. I don't feel like researching the stats, but I'm sure Manu scored more than Duncan in the 4th in close games through '05 until now.
Just post the overall stats from those games. Kobe outperformed Duncan overall anyway in the majority of the games you referenced, so choosing to focus on only the 4th is superfluous.