What do you mean by the same place? Generally Apple has completely separate iCloud areas for different accounts. It is possible to share some items such as photo albums --> https://support.apple.com/HT202786
It is also possible to share storage but you are not going to share the same content. It's more like one person buying a house but then letting others have their own rooms in the house. Each user's space is completely isolated from others in the Family Sharing group.
Given how Apple has things set up, you should be able to delete one account and the other remains unaffected, but it would be good to know what you are seeing that makes you think there is shared content. An alternative to deleting an account would be to deactivate one of them and then see if it affects the other. If it does not then you could later delete it. If it does affect the other, reactivation is easier than trying to undo deletion which is impossible after a time.