Child NetworkIdentity

Hello!
I know it's bad but ..

What happens with network object (A) spawn from server registered spawnable prefabs [have LocalPlayerAuthority in NetworkIdentity and AssignClientAuthority(connectionToClient)] after placed in the hierarchy of the player object (B) and disable NetworkTransform (A).

Looks nice and works fine, all clients see the correct movement of the object (A), equal player (B), even after it is thrown out of the hierarchy into the world and NetworkTransform turns on (A) it can be picked up again. But something is wrong, there are some incomprehensible behavior from time to time.

Why so it is not necessary to do?