Eliminating the two Higher Lifeforms on the battlefield created an opening for the Valyrs and Untamed Awakened. They didn't have to worry about getting overwhelmed and could dominate their enemies instead.
However, the battle was not over with the death of the Higher Lifeforms. It had just begun.
Even though the battle had just begun, Michael was quite satisfied. He and his people were at a great advantage against the Council of Xylon because there shouldn't be more than one or two Higher Lifeforms in every territory. Many Lords didn't have a single Higher Lifeform in their territory. The only reason those Lords survived so long in the Savannah Region were their extraordinary defenses and business-oriented alliances with the Lords living adjacent to their territories.