Another question begged is, did the Amalekites slaughter defenseless children when they attacked the Israelites? What kind of culture, then, were the Amalekites?—we see child soldiers even today, not exactly defenseless.
Like I said, I wasn’t there. I suspect you weren’t either, but then I’m presuming you aren’t in possession of a time machine.
If American troops encounter child soldiers, are they commanded to exterminate them down to the last breathing soul, or disarm them and help them? Does it matter what the Amalekite adults did with respect to how to treat their children?
Why in the hell are you defending the indefensible, instead of accepting what common sense tells you:
There's no cosmic authority in the OT. It is a Bronze Age book filled with Bronze Age morality. End of story.