As for numbers inflation being proof that the Bible is spinning a total yarn... I guess accounts that attest to the existence of the Battle of Thermopylae should be thrown away completely as well, because they claim the Persian Army to have numbered over 1,000,000 men (Herodotus puts the number at almost 2 million)... a near impossibility.
To say nothing of Roman accounts which, if taken at face value, appear to indicate that they committed genocide every single time they won a battle.
If we're looking at the OT as a primary source for serious history, then there's only one way it which it can be considered; as the collected oral history and traditions of one particular society.