To me two things are clear: God is a warrior God, there is even texts that talk about biblical battles from other points of view, like Sumerians. The second thing is that God, being God, can easily decide what action will result in wa outcome he wants, even if it require sacrifices. Like when you have one parachute and two people in a airplane. Not always is possible to save everyone.
Yes, but did you noticed a pattern where God leaves most stuff to humans to do?
Even some miracles are not miracles (ie: Jericho wall destruction, God explained what people had to do, but if you pay attention, it was a matter of physics, not supernatural power).
He didn't leave the killing of Egyptian children to humans, nor the razing of Sodom. You flat-out ignored my first question, though, so I can tell you really don't want to debate. Let's just stop this here.