You don't get any more "hearsay" than oral histories passed down through multiple generations. That's about as unreliable as it gets.
If you want reliable, read things that were written by the very people who lived through those events. That way, you are getting it in the words chosen by the people who actually were there, written in their own hand so you know it hasn't been changed or distorted by subsequent listeners.
That still isn't perfect, because individuals have their own perspective and viewpoints that may not reflect fairly what actually happened. It's like pulling a random 70 year old off the street 40 years from now and asking them about Trump. Exactly who that person is would make a huge difference in terms of what you are likely to hear.
Academics are the worst to distort history. Those who survived great calamities, know far better.
You don’t know anything about me. My family has owned/operated farms in this county since 1889, prior to that in Texas from the Republic of Texas. WWII vets taught me to hunt, fish, work and told me about people I never knew.
Prior to Texas some of my ancestors came from SC to GA and to NE AL. They experienced events that were seldom talked about in public for a reason.
When I graduated from College in 1970, I was burned out of reading stuff I did not have an interest in. In 1976 I found a copy of The Bodyguard of Lies, by Anthony Cave Brown. It was published right after the freedom of information act unsealed a lot of WWII events and methods. I spent 9 years reading everything I could find that related.
I got my first Amateur Radio License (advanced) in 1976, my Extra in 1985, my GROL Commercial in 2000. This fit right in place for understanding some things we did with RF and electronics. I was living in NM at the time, among lots of great Electronic Tech, Engineers, Physicists. Had family in the weapon’s business.
So, I don’t make up history. I try to understand it. It still continues today. I am 76.