depends on how you look at it, theyre the cost of an additional card and additional quanta, essentially with premade immortal creatures youre paying for two cards in one, but when you using quint or pa, you pay for the base card and then use another card and pay for that one as well.
concerning the "strong against reverse time", im not so sure thats a bad thing to have an alternative vulture model which does not share the same strengths or weaknesses. that said, it may warrant an additional quanta or two