When you instantiate an object, TNet will give it a unique ID -- but only one. If you have nested TNObjects, they won't receive unique IDs because the order in which they can appear via GetComponentsInChildren is not guaranteed to be the same, so you may end up with RFCs going to the wrong objects.
The only way to do what you are trying to do properly, is to use only one TNObject/TNAutoSync script, and just referencing child's fields along with the object's.