Responses
I don't think that they are the grown up version of the kids, but I think that Guwon saved them when they were young and raised them.
And the kids are potential replacement for them if they die.
Remember everyone in the village were saved cause they were useful and have a purpose.
If they don't, Guwon would have killed them.
This is what I think ╮( ̄▽ ̄)╭

Wait wait….what if these squad leaders are the grown version of the kids?!? They are three, have too much facial similarities, they can have coloured hair and also personality traits vise…like Heewon being the closest to Guwon just like the girl child…