The point of my argument was to say that a complete pre-flood civilization existed which produced massive cities on the scale of what exists today
Really?
I've just returned to this forum after several years away, so maybe you've already done this in another thread, but what is your evidence of this? Surely, if there were cities of the scale of NYC, Mexico City, and Paris thousands of years ago, there must be tons and tons and tons of physical evidence. I mean, where are their garbage dumps?