You use common sense you are ignoring the authority Kong has. Akainu has movr narrative importance so is shown more. Akainu is shown more than imu and imu has never ordered the maines to do anything. Most of the wg doesn't even know about imu so akainu is above imu by your logic right? Fanboying has its limitations you can't rewrite what's in the manga. Kong has a higher rank than akainu and has vastly more authority than akainu.
We know Imu has authority because we see him order the Gorosei around. We don´t see Kong order anyone around with his position, in fact it is the Gorosei who actually give the marines orders. Even for something as minor as Kuzan leaving marine hq to go biking, the marines instantly contact the Gorosei,ignoring Kong completely
Kong is also not at the warlord meeting in Jaya, even though on paper it could be his job, instead Sengoku is sent to deal with it.