On the flip side...

In halachic discussion the intellectual truth is what holds sway. History is irrelevant. Which of the parties in the discussion lived when and under what circumstance is all irrelevant. Rava says... Rashi says... Rav Gifter says... Alive or dead the truth is the only thing that matters. We in learning the opinions and the sides of the debate are the arbitrators. Our arbitration may lead us to a different conclusion than that of the arbitrator from 100 years ago and that's OK.

Also, regarding the need for a historical truth to Jewish historical events. Do we need to answer the question of "What if it didn't happen"? A first reaction might be "of course we do!". If it didn't happen why would keep to the religion? On the other hand if Shmuel HaNavi made up the character of Gideon to tell us a moral lesson of leadership pre-monarchy would it shake our faith in God and Torah?

So why study history?

For halachic discussions, history may give a better understanding of each theory. By knowing when and how each debtor lived we can better understand their statements. Knowing medieval French may help us understand an explanation of Rashi. Understanding Arabic may reveal fine distinction in Rambam's writings that we were previously unaware of.

Regarding historical truth of events I feel there is a difference between the historical accuracy of Sinai vs the historical accuracy of Gideon's battles.