In a war of gods, using the collision strategy of the God Kingdoms was a well-known method.
After all, the God Kingdoms were agglomerates of massive amounts of Divine Power and were the gods' strongest clones. To each god, the God Kingdom was his main and actual body. To the gods' systems, the God Kingdom was the combination of all the gods' powers.
It was needless to say that in the case where one simply wanted strength, everyone would focus their powers on the God Kingdom and use it to knock down the enemy as it was both a useful and powerful move.
There was no greater method than allowing a God Kingdom to self-destruct.
Self-Destroying a God Kingdom meant the downfall of the gods, and using this method meant one was ready to perish if it was so. In comparison, the mere collision of two God Kingdoms was less cruel, and there was still the chance of one side emerging unscathed.