The word 'gandhabba' refers to whatever else is required beyond the other two conditions of the woman being fertile, and the coming together of the woman and man. As has been pointed out previously, there's not a lot known about precisely what the term is referring to.
"Do not force others, including children, by any means whatsoever, to adopt your views, whether by authority, threat, money, propaganda, or even education." - Ven. Thich Nhat Hanh
"The uprooting of identity is seen by the noble ones as pleasurable; but this contradicts what the whole world sees." (Snp 3.12)
"To argue with a person who has renounced the use of reason is like administering medicine to the dead" - Thomas Paine