The Babylonian War was between the forces of Antigonus I and Seleucus over the satrapy of Babylonia. The war was won by Seleucus and India, Afghanistan and Pakistan (under the Mauryan Emperor) gave him a force of war elephants. With which the Seleucid Empire expanded to absorb Iran and parts of Afghanistan, making it the most powerful Empire since Alexander. It also ended any hope of Alexanders Empire being restored.
What if however the Antagonids won, capturing and executing Seleucus? Would that give Alexander's Empire a chance of restoration? Was it just to far gone?