Let me add another “inviolable rule” to the set of rules that I posted earlier:
The following must hold:
1. A given gandhabba can be in only one body at a given time.
2. It is possible for a gandhabba to come out of a womb (detach from a zygote in the womb), and for another gandhabba to take possession of that zygote in the womb. A gandhabba getting hold of a “dead body” of a full-grown person or even a baby is dubious.
3. A gandhabba cannot decide to take hold of a zygote, a baby’s body, or an adult’s body. That is determined by nature (laws of kamma).
I think we should not get carried away by some of these accounts.