(How to understand this structure) The schools would seen very impersonal were...
The schools would seen very impersonal were all the computers to replace human teachers.

How to understand its structure.

Question

(How to understand this structure) The schools would seen very impersonal were...
The schools would seen very impersonal were all the computers to replace human teachers.

How to understand its structure.

Answer

It is another way of saying - if all the human teachers were replaced by computers, schools would seem very impersonal.