@Thekillman. Wait, that actually makes sense. Naruto's Kurama chakra unintentionally boost up any closely wood releases. So I guess Naruto using Wood release could be dangerous considering that we seen Danzo's whole hand turn into a tree when he lost control of it.
So I think from the information gathered from the previous transplanted WR users, Tsunade designed this hand to just give the access of enhancements in body and power rather than acces to wood release. I mean she did make this hand right?
And well they were ready to give Sasuke a whole arm amount of Hashi cells to him. Not saying that they don't trust him, but maybe they locked the Hashirama cells power or something, so both Naruto and especially Sasuke won't go crazy or be unable to control the power?
And do we really know how Hashi awakened his KG? I mean KGs so far(other than Naruto's tailed beasts's case) were awakened from a sudden need without any intention from the user itself. So in the war period, as even a child, Hashi would be strong, but there would be atleast stronger adults that came at him, that he was cornered at? could he not awaken it at that time? By this I mean is Naruto and Sasuke don't have anymore emotionally effective death threatening attacks at them anymore. So basically they atleast need to awaken it like how Hashi awakened his(I mean he always had his cells in him, so if it isn't a awakening thing then he should have easily done it as a child).
@GenkiGat. I think there's a specific size for a jutsu. Giving more chakra then it should have would be wasting it, but Chakra power does come in this. If Naruto possibly could do it, then he could make a much stronger one not a bigger one.