Let's get the negatives out of the way first.
Yes, the geek kid is extremely annoying. But his character does experience growth. So there's that. Also, the guy playing Caspi over acts as well.
As to people moaning about bad dubbing, why are you watching a dubbed version? NEVER watch dubbed versions of anything. On Netflix, in particular, every show that is dubbed is awful. Great shows like "Money Heist" and "Babylon Berlin" sound like high school productions if you watch them dubbed. And, yes, there is both a dubbed version and an original language version available of "Valley of Tears" on HBO Max. So, stop complaining if you're not watching with subtitles.
But, all that aside, this is a pretty mesmerizing show. It really sucks you into the moment in time. Many of the details are accurate depictions of the chaos and noise, fear and horror of war. No, not everyone marches into battle like John Wayne or leads troops expertly like George Patton. I appreciate the reality of it all. Together with "1917," these are two of the best anti-war films in a long time. And, yes, pretty much all war films are anti-war films.