Think about it:
Before, even if Sasuke made Naruto the core, Sasuke would probably run out of chakra before all the rocks engulfed Naruto (assuming Naruto was destroying them as they came to him)
NOW..
Sasuke has an unfathomable amount of chakra, all he has to do is thunder clap, put Naruto as the core and have the rocks keep coming. Naruto will for sure run out of chakra or at the very least, stamina, before all the land is used up as rocks for CT.
Before, even if Sasuke made Naruto the core, Sasuke would probably run out of chakra before all the rocks engulfed Naruto (assuming Naruto was destroying them as they came to him)
NOW..
Sasuke has an unfathomable amount of chakra, all he has to do is thunder clap, put Naruto as the core and have the rocks keep coming. Naruto will for sure run out of chakra or at the very least, stamina, before all the land is used up as rocks for CT.