> It's more likely that a Holocaust denier would have luck convincing someone if the commonly touted numbers are inaccurate and vociferously defended.

Why do you think Holocaust deniers are hell bent on nitpicking about these estimates? Their tactic is to use them as a wedge to push other bad faith arguments to cast doubt on all aspects of the Holocaust. Again, do you think it makes any difference if a gross estimate is 5-10% over or under? The strategy followed by Holocaust deniers is to abuse this logic to jump to conclusions like "if they are wrong about these numbers then what other lies have they been pushing?"