Shen's base stats are horrid. Oh, and Sion's.
I've been doing some data analysis, so far just creating a matrix of champion tankiness stats, and how they compare to the average. As I was reviewing the data, I discovered two outliers that shocked me. 1) Sion is worse than the average in terms of both physical and magic damage. (Effectively requiring 10% PD and 3% MD less damage to kill than the average.) And 2) perhaps more shocking, Shen is down 2% PD and up 3% MD compared to the average, though most tanks are 6%+ over the average at least. (Note that the numbers I provided are the averages over the course of the game, and the champions level.)
This shocked me because, first, Sion is always considered a mega-tank, but in actuality he's way worse than the average league champ if it weren't for his health stacking W. (in terms of base stats anyway. His W is also a shield, and he's just as much a threat dead as alive.) Secondly, I'm shocked because Shen's always felt kind of tough to me and now I know why. He needs to be tanky in order to do his job, but before he gets items (which he has trouble doing since he's so vulnerable to harass) he has some of the worst tank stats in the game. (Most tanks start off and end way better than him.)
Anyway, I just wanted to write that out because it weirded me out. Have a good day all!
~CrimsonCobra3