EXTRA:
If it were up to me I'd make sure to kill every one of those other world travelers. They're so cocky and never have second thoughts when they get a mission to kill a bunch of innocent, peaceful people. Monsters or not. I don't care that they're from the same original world, or that one was Shizu's disciple. Killing innocent, peaceful people without a second thought just because some king told them to makes them evil in my book.
From what i remember, they are bound with spell.. so that they cant refuse their summoners/master orders.. i think rimuru and veldora talk about that in the cave.
Good point, but even if that were true the main other worlder group is still so uncaring about it. The only one who seems to really object to it is Shizu's student. So I guess she could be forgiven. The others though, having to follow orders or not, they didn't seem to have any problem killing innocent, peaceful people. Sure they were "monsters", but still.
They sneak attack using underhanded methods like the forcefield that weakens monsters, trying to provoke the monsters and when that didn't work killing them at random anyway, and keeping Rimuru away from his city. Yet they dare to now get surprised and even scared when Rimuru's forces retaliate. Well, now that they've lost that first element of surprise they're the ones getting slaughtered. Serves them right.