Yeah, in an ideal, utopian world that'd be the case. In such world, however, war wouldn't exist to begin with. You're creating a fantasy to justify your bloodlust.
A soldier going out there to kill monsters is not a "racist murderer". Even if we assume that most of these soldiers were bad (it's entirely unrealistic to assume ALL of them were bad), that doesn't justify killing them without mercy, because, as shinta said, people can change. And Rimuru of all had the power to force a change. He chose not to because resurrecting his friends was more important to him. Which is understandable on a personal level. But it's not a moral choice.I disagree. The people Rimuru wanted to resurrect were innocent. The people he wanted to sacrifice were racist murderers.
Again, it comes down to a trolley problem. Racist murderers' lives are not worth the same as innocents.
Here's a thought experiment: Would the 100k soldiers still be alive, at least some, had Rimuru not had the option to resurrect his friends? The answer to that tells you everything about Rimuru's morals.