so what?? there is a Moses...and??
he didn't perform miracles/etc
How do you know he did not do things that we do not yet understand, like the Voodoo zombies? Voodoo has long been dismissed as just another superstition, until a biologist explored the topic and discovered that the zombies were real, but due to magic, but due to herbal toxins that acted on the nervous system.
Why could it not be a similar case with Moses 'miracles'?
Suppose he had knowledge of a previous similar disaster, and exploited it, led by voices in his head he identified as the Creator, to achieve the liberation of Israel?