I guess to me, they’re still fighting faceless people who, recruited as children or not, take part in multiple genocides, and those who were less directly involved cheered it on.

I don’t feel like our heroes become heartless because they prioritise the needs of those who can’t defend themselves rather than feeling bad for genocidal armies.

I feel like Finn having been one of them, and with how we see his defection and actions against his former comrades, he seems to show that he knows they are who they are. He thought himself to be the only one to question what they were doing, which is why he’s so shocked to see more (in Jannah and her crew).

These troops are all adults, joining as children or not they have chosen to commit such atrocities that I don’t feel their deaths harm the way we see the heroes or their actions.