After Kaguya was introduced the logic just went down hill. If Kinshiki and Momoshiki were feared by Kaguya, Why didn't she kill them already?. I mean Hagoromo was the one to preach Ninshu after sealing her off and the fact that she knew of their existence means she considered them a threat before her being sealed, then again, If before that no one knew how to utilise chakra and Kaguya knew Kinshiki and Momoshiki existed how could they know how to use chakra? And rinnegan was something even Kaguya got from Juubi and Hagoromo's were not stolen, so how the heck could they posses it already? and if they didn't have rinnegan back then they shouldn't be much of a threat as they couldn't possibly have absorbed chakra which I wonder how they learned to use it since the only people born with it were Hagoromo and sibling?