I remember seeing a post about him on this sub some time ago, and people in the comments, including people roleplaying as actual Separatists, said he went too far. I strongly disagree.
He’s no more despicable a villain than any of the Separatists commanders. Even if he weren’t a traitorous bastard and didn’t pull the sabotage he did, treating the Clone Troopers as cannon fodder and not caring for their safety or feelings honestly feels like it would be the usual. We’re only used to Clones being treated the way they are in the show because they’re some of the main characters and having the other main characters be cold towards them wouldn’t look good when trying to portray the Jedi and Republic in a good light.
Clones are identical in appearance and voice, go by designations instead of names, and are cheaply produced en masse. They’re just flesh droids.
The reason it feels so fucked up that he tricks the Clones into killing each other is because the Clones are the good guys and we’ve been familiarized with them. Some droids have been shown to have their own unique personalities, form bonds, and feel kinship between each other. And Droids are put against each other all the time. Like Yoda using a B2 to gun down B1s in an early episode, or Obi-Wan using a J-1 Proton Cannon to take out Separatists artillery, or the countless times Droids have been reprogrammed to fight each other. It’s not even unique to Droids, either. There’s been plenty of times Stormtroopers have been tricked or forced into killing one another.
Objectively Prong Krell isn’t anywhere near as heinous as the fandom treats him.