Student's address vs Customer's address

ERPNext Education
1

Student docType has a [TAB] named address.

There is address under CRM. When we create a student, it also create a customer for him/her, that means student is also a customer. If that is the case, then why we have not used addess of CRM, rather having address as a [TAB]. There might be two childern of a teacher studying in the same school. That mean one address of CRM-> Address can be used at three places.

Why we are having duplicacy / redundencies, which are not supposed to be in any ERP?

2

Student docType also has tab [Relation], where we can add sibling. If sibling is Studying in Same Institute, then Gender, DoB, Program should be fetched automatically, there should be no need to add manually.

If male student is entered first, as A. On entering his sister later as B, we can tell ERP that A is sibling. The system should also update that B is sibling of A automatically.

Is it possible?