Aboard the Marine warship, Akainu still looked as though everyone owed him money as he stared darkly at Whitebeard and the others. He followed Absolute Justice, meaning that all unjust beings should be destroyed, but ultimately, what was just or unjust was entirely up to him.
Pirates were naturally the greatest of all unjust beings, and the Four Emperors currently ranked among the greatest pirates. Given Akainu's thinking, he naturally wanted to wipe out Whitebeard and his entire group in one fell swoop, but he clearly could not accomplish that alone.
As for Aokiji, he could be considered a more humane person, as the Ohara Incident showed. Back then, the orders from above had been to wipe out everyone on Ohara and erase the entire island from the map, and Aokiji had been one of those tasked with carrying out those orders.
Had he followed those orders strictly, Nico Robin, as one of the island's inhabitants, would never have stood a chance. Never mind that she had been a little child at the time-even the Robin of many years later, whose dark skin had turned fair, would have had virtually no chance of escaping the Buster Call's blockade alive. Yet because of his friend Vice Admiral Saul's dying request, Aokiji had actually let Nico Robin go.
Not only that, but Aokiji's usual way of doing things was very different from Akainu's. If Akainu himself considered it necessary, he could disregard civilian lives and even treat the lives of Marine soldiers as worthless. Aokiji, on the other hand, was the sort who respected life, or rather, was more merciful.
In fact, logically speaking, neither of them was particularly suited to becoming Fleet Admiral. Red Dog was too violent and radical, while Aokiji was too conservative. A combination of the two would