Scythe had no issues as far as we knew, other than being quick to make rash judgments. But I just wonder how it could be done to this extent, since our creation would've been far before he'd have been born.

... though, to be fair, we don't exactly have much experience in terms of how humans could look like us, or even be compatible with us. Those like Kai, Koyo, even Alexandra, or even the fact that Scythe had managed to possess this "Mamoru"... before recently, it was unheard of.

Then why don't you examine them, even separate from my own concerns?

The way Kai put it, my actions seemed to put him through an incredible amount of stress.