Well, paganism was about finished anyway. Socrates and Plato blew its head off with a shotgun, and then the Roman legions steamrolled over its dead body. That's the first thing to note.
If Christianity didn't "make the cut" a pseudoscientific gnostic cult (e.g. Manichaeism) would've taken its place. Christianity suffices to say "God created the world and sometimes performs miracles within it" but doesn't bother to try to explain the mundane workings of the natural world and explicitly forbids such practices as astrology and divination.
That is to say, in an environment where people knew next to nothing about science to begin with, it did way more good than harm via imposing a stable framework for a thousand years where unknown elements of the world were to be explained by means other than sorcery or magic or witchcraft. With there being no god but God, you couldn't say "Lightning is caused by Zeus!" or "the lunar cycle is caused by Artemis!"
And yes, the natural world was governed by knowable rules because the God who set it all into motion was a God of rules.
In theory one could've substituted for the polytheistic gods by saying "God directly causes every effect in every moment" but Christianity never seriously went down that path anyway.
(That's not to say that there wouldn't still be some people making scientific inquiries, but I imagine the rate of progress in discovery would've been slower.)