I think equating belief in Napoleon and God is a false comparison, or rather it does not support the conclusion you imagine:

One can posit that Napoleon or the moon landing are made up, rather than real. But now one needs to examine whether the evidence can support these alternatives. There is a tremendous amount of triangulating evidence (diaries written by soldiers etc.) that support the idea that he existed. One would need to construct a narrative where a great hoax was played in years in the past. and a hoax where the losers in battles killed themselves in order to maintain the ruse.

It becomes untenable, thus the conclusion that he existed becomes more certain.

The moon landing, or the existence of shakespear are more suspect, simply becuase the amount of assumptions one needs to put into place to support an alternate theory becomes less and less.

In this same way, theories that God does not exist have very plausible alternatives. Thus this 'fact' is not proven to the same level that Napolean's existence is proven. (and 'proving' he does not exist is also problematic.)

I dont think it is on the same level as Napoleon.