Playoff Series Imponderables

[Dahlsim]

Very interesting points. The ultra-tall stats regarding lack of durability actually referred to players taller than 7'1," but it seems that comparisons to seven-footers might still be apt. Also makes sense that playing style and playing patterns could affect longevity in big guys.

I don't doubt that the Ultra tallness creates longevity concerns, wear and tear on the feet, bones, ligaments and just additional stress.  
I think its one factor though, not the entire picture.  

Obviously there is the weight and body structure but alsl the pure number of times a player is jumping, and the style of play in terms of the type of jumping, height etc. has to be relevant to the impact and total stress measurable over time on the areas that are known to cause problems in the big men. 

Not sure if there is a big line to be drawn between the 7 footer-ish big man and 7'1" + Big but there are clearly other factors in terms of injury and durability. 
As I said Shaq went 19 years but yet Greg Oden, "just" a 7 footer didn't lasted barely a 100 games over the course of less than 6 years. 

You have to also look at the player himself and how he cares for his body. 
Tim Duncan & Dirk had awesome longevity but Andrew Bynum came in strong only to flame out early, sticking around a few extra seasons stealing paychecks. He was evidently not exactly one to help his body out with his lifestyle.    The style of play is huge, the demands of the team based on who the player plays with is huge alongside obvious work ethic and diet. 
For that matter even Luka's longevity and risk worries me the way the Mavs are using him without enough star help to cary the load.  

Boban is interesting to me because he barely jumps to get a rebound, shoot or even dunk!  The impact there is much less than some other smaller big men.  

Porzingis on the other hand, at his height playing like a high flying small forward, or banging high minutes, jumping high (and landing), because he can, to block every shot and get every rebound at 5 against NBA strong men, yeah, he would worry me in some ways more than Marjanovic. 
Adjustments to his style of play could help reduce his risk I think.   If KP can be a real sharpshooter, those player can extend their careers at any size.