Each of the four had their own advantages.
Ōnoki was the oldest and the most experienced, unquestionably a seasoned veteran.
Ronglin was the strongest, and Konoha behind him was also the strongest among all the villages. If those two competed for the position, their chances of success would be the highest.
Ay was relatively young—though this referred not to his actual age—while Rasa had the least hope.
In terms of strength, Rasa was neither here nor there, and his village was even the weakest. What right did he have to compete for the commander-in-chief position?
How many supplies could Sunagakure even provide?
It was inevitable. Ronglin found Rasa's attempt to compete for the commander-in-chief position rather amusing. Ambition was a good thing, but before having that ambition, one had to make sure they possessed the strength to back it up. Ronglin stared at Rasa, thinking that Rasa was the one who had leaked the results of their previous discussion.
He himself had never done it. Ōnoki could not possibly shoot himself in the foot, and Ay's personality was not suited for scheming or stabbing people in the back. It did not suit Ay, though he could not be entirely ruled out. Still, judging from the emotions he had displayed during their earlier argument, Ay was basically eliminated as a suspect.
That left only Rasa.
I, Uchiha Ronglin, have treated you and Sunagakure quite well. Was it really appropriate for you to screw me over?
But since you had already decided to screw me over, then do not blame me for screwing you over every step of the way from now on.
"Cough, cough! I believe it would be most appropriate for me to serve as the Allied Forces Commander-in-Chief."
After Ōnoki, Rasa, and Ay exchanged a meaningful glance, Ōnoki quickly