all i'm trying to figure out is how the HELL did Zeke freaking rat out his family and grou...

Maybe like erwin's case? Or zeke just pure evil? U can read this kind of reference in 1984, when children rat their parent to "big brother"

The Mare deliberately wanted to recruit and choose children ages 5-7 to become the new shifters. Children no matter the age are developing and are thus susceptible to 'brainwashing'. shi-en-ta is correct in the children ratting out their parents or just those around them to the government. A real life example would be the Hitler Youth.