There was no way that the Gibson film was going to get big sutdio financing. Serious films about religious subject matter had been box office poison for decades.
Last Temptation of Christ got industry support and in fact the very production had been branded an “urban rumor” in one book on such things (William Poundstone’s Bigger Secrets if I recall).
Mirimax release the movie Priest on Good Friday and claimed it was a mere coincidence.
Hollywood studios have been decidedly antiChristian in the past 20 years.
Hollywood is petty and studio bosses will kill the promotion of a film on whim and personal bitterness even if it costs the studio money. Read the book The Battle of Brazil.
Gibson didn’t need studio financing, but he “needed” distribution.
Stargate was made without studio financing, if I recall. Make a film and then find a distributor (just like the small filmmakers).