Firstly, the standards expected of jōnin are likely to vary, from village to village. Further evidence:
- Sunagakure is considered the weakest village, at least out of the Five Great Nations
- their shinobi populace took a plummet after they attempted to invade Konohagakure
- this is reflected in even Konohagakure; when Kakashi was made jōnin whilst still a kid
Looking at
specifically the jōnin of Konohagakure, they had
solid stats in the three main shinobi skills.
- Sakura's are lackluster, with a 3.5 being the highest of three
Of course, none of this takes into consideration that Sakura is an emotional wreck.
- jōnin are expected to operate alone and without any self-impairment