Attachment in engine is one way, if you attach something to a parent, only moving the parent will move the child. The only exception to is if you are using a physics force or constraint to move the child and you weld attached them together and they are simulating, then the child can move the parent as well.
If you want to do it without physics then the easiest method would be to “promote” the grip to the attach parent when you go to grip. IE: search up the chain of attachment parents for the top most and grip that at the same transform.