The BSM punch is for itself. When Naruto punched Toneri, Naruto's entire body felt the shock of the recoil. Like I said earlier, it's like when you push a truck forward by pressing your two legs against the ground for better balance and position while your two arms push. You have to have strong legs to halt your movements from moving back while your hands should equally be as strong to push forward.
If we were to calculate the crater like you said, it wouldn't make any sense. It's like saying this
Is stronger than this
based on the crater size despite the smaller crater being from BSM Naruto's full body unlike the base Naruto with Kurama chakra coated.