He was never punched by Karin and punch wounds can't be compared to having internal organs damaged. Furthermore, chakra recovery isn't a big deal for him I'm specifically talking about cell regeneration.
As I said before, the healing in VoTE 1 was done on Kurama's will not Naruto's. The only time he regenerated his body on his own accord was when he got RSM because it gave him full understanding and control over chakra, in other words Naruto and Sasuke haven't lost the feats they showed at the end of the manga.
i know for absolute certainty that you are wrong on both counts, because Omoi had to stop her from punching him after Naruto told Karin that he didn't want to tell them anything.
Secondly, it was never established that Sasuke's sword ever got any of Naruto's organs.
Third, in the instances where Naruto suffered what was seemingly a serious injury (
Naruto getting hit with Chidori at the 1st VotE fight & the recent chapter), the bijuu shroud was active. What Karin and Kiba did to Naruto was mostly superficial damage, so it wasn't exactly needed.
Point is, it's jumping to conclusions to say Naruto restored his own organs when he got stabbed when it was never mentioned or shown that the sword got any.