Take the zero away and the Celestials still win. A starving Galactus wrecked galaxies. Yet Galactus still had to consume four planets in order to face a small group of Celestials. He defeated one, but then got one-shot by the other three.
It being "random" Celestials doesn't make that much of a difference. The power level between the majority of Celestials is not that vast. Sure, there are top dogs between them, but even these top dogs have been stopped by 2-3 random Celestials on certain occasions.
5 random Celestials are more than enough.