In the Summit War, among the highest-level combatants, only Akainu fights desperately from beginning to end. The others are either letting things slide or goofing off.
In the Summit War, the most qualified soldier is Akainu. As for Koby trying to block Akainu, to be honest, under the circumstances at that time, it would have been lenient for Akainu to kill Koby directly.
Koby is a deserter, and when he blocked Akainu in the end, it was equivalent to disrupting the morale of the army. The Marines already had the advantage.
Although the nature of Blackbeard's actions has changed, the Marines could have kept a few more captains and other members of the Whitebeard Pirates.
Without even thinking about it, they knew that once these people escaped and stabilized, they would definitely attack the Marines. After all, the Marines killed so many of them. However, the Marines' behavior at that time broke up the last bit of morale on their side. So, after Shanks appeared, Sengoku and the others followed Shanks' lead to save face and stop the war.
Koby got to stay in the Marines and even got promoted later on, but only because of Garp.
Basically, if Akainu was the best soldier in the Summit War, then Koby was the worst. Way worse than any of them.
Aokiji's words made Sengoku and the others agree. They were right. Even ignoring everything else, if these Marines kept making powerful enemies or even joining the pirates themselves, it would be a huge hit to the Marines.
This time they got lucky. Luo Ning didn't kill them at all. Otherwise, the Marines who went to Impel Down probably wouldn't have made it back. If they lose all those strong guys in Impel Down for good, the Marines are in big trouble.
This whole situation will just keep getting worse and could even destroy the entire Marines.
"We'll set up a team to clean the corrupt after your proposal, but that's for later. By the way, how's your injury? Any idea what's wrong?"
Sengoku glanced at Aokiji's pale face. Now that the immediate issue was handled, Luo's ability was next. They needed to figure out who or what he was exactly.
Even though Luo didn't seem hostile towards the Marines, their business was left unfinished. Onigumo was still messed up in the hospital.
Forget about fighting Luo head-on for now, they definitely needed to be prepared and understand his powers.
"No clue. No wounds, organs seem fine, but the pain keeps hitting me hard"
Aokiji was as lost as everyone else.
"I gotta get checked at the hospital later. This ain't sustainable. Now, let's talk about what we know about that guy's powers..."
Sengoku started listing Luo's known abilities. By the end, they all agreed - he was a freak.
"The big question is why seawater doesn't affect him. All Devil Fruit users fear the sea, so maybe he's not a Devil Fruit user at all. But then how does he have all those powers?"
Tsuru's question stumped everyone. They just didn't understand.
"If only we could get a blood sample..." Sengoku muttered suddenly.
"Forget about it! No way we're getting blood from that freak. I fought him for hours and couldn't even scratch him. How many of us here are stronger than me?" Garp shut down Sengoku's idea immediately. The guy was like iron - way harder than steel. His punches could level mountains, yet after hours of fighting, Garp couldn't even break his skin.
Garp scoffed. In terms of raw power, nobody here beat him. Kizaru and Akainu had strong attacks, sure.
But Garp doubted either could break through the other's defenses.
"Agreed with Garp," chimed in Gion. Having fought Luo Ning's clone, she knew firsthand how terrifying his strength was. Just a copy pushed her to the limits.
He let them go this time, but what about next? What if the Marines were wiped out? All things considered, picking a fight wasn't wise.
"Alright, intel gathering it is then," Sengoku conceded. "But Sakazuki..." He winced at the thought of Akainu. Akainu's personality was a ticking time bomb with Luo around. Once Akainu got involved, war was inevitable. A good fight was one thing, but what if they lost? That'd be a disaster.