Context: Modern historians debate and argue over historical events. Meanwhile the sage Vyasa dictating the Mahabharata to Lord Ganesha, showing that ancient historians simply recorded massive, made-up casualty counts - something shared across the globe.
I’ve read a shortened version - I found it lacking in comparison to a modern fantasy novel. I didn’t really care about the characters, their motivations were strange, the build up to the war felt forced, it’s unclear why seemingly every leader in the world cares enough about the brothers’ conflict to send their forces and have them all die, and it wasn’t clear how exactly the heroes were killing so many enemies so quickly (thousands in a matter of minutes I believe?).
But then, making any sense might be irrelevent for the function of myth.
you may have read too short a version - the best i can do is a watch some 240 hour video adaptation, which is non canonical as hell, and a russian dub is available online.
as some one who knows it somewhat -
it was a bit more than brothers conflict, think more in line of atla - who should be fire king - ozai or zuko (ccomparison is fair because both are fantasies).
that is mostly heavy exxageration.
depending on “stuff” total death toll of battle could be in range of 100,000. but basically putting any number is just as wrong.