If you want a typically OT response to your “question,” then look no further than Ecclesiastes, by which it is clear that you are being unnecessarily moralistic and are assuming that life is an ultimate good, and death under herem an ultimate evil. According to Ecclesiastes, however, everything ends in vanity. Consequently, it is irrelevant how someone dies. The only good is whether they followed God’s commandments in the time they are given.

Additionally, it is critically important to note in this debate that Israel’s perception of God’s “overreaching” judgment is not limited to their enemies, In fact, most of the biblical narrative concerns God’s activities with Israel, which include multiple destructions and exiles as well as periodic divine plagues and threats. In this respect, the Bible fundamentally grapples with suffering and death, and the uncertainty of life, yet in contrast to most Mesopotamian literature still affirms the ultimate goodness of God, whose ways are (a) often inscrutable and (b) not subject to human judgment. The goodness of God is demonstrated through creation, his acts of unfailing love and steadfastness towards those whom he favors, and his will that all people should have access to him, including Israel’s greatest enemies, Egypt and Assyria. This, according to the OT, is sufficient basis for belief in God’s goodness.

You (and other readers thinking about these issues) might find these two essays helpful: How could a God of Love order the massacre/annihilation of the Canaanites? and Shouldn’t the butchering of the Amalekite children be considered war crimes?