Besides, these severe punishments for iniquity are not necessarily eternal. The wages of sin is death. But our God, that same Lord of hosts, the Commander of the armies of the Lord, has overcome death. And He can raise them up in the general resurrection and give them their day of salvation. So in the end, I say this kind of flippantly, but no harm, no foul. He was moving His purpose forward and did that as Commander of the Lord's armies to move the purpose of God forward because that is what God had told Him to do.
We know from Revelation 20:11-13, that these people who were annihilated on earth in their day will come back, and they will be given their chance for eternal life in the Kingdom of God.