We don't know what level they were at at that time, who fought who, and what went down.
Except in Akainu's case, it was given to him specifically because of his strength. We can't say the same about Sengoku because we don't know how he achieved that rank.
You're reading a shonen
They merely cancel each other out lol. Go look at a video of lava being poured over a block of ice. It's not what you expect.
So your saying to me WG wanted Garp to be a Admiral or even a Fleet admiral wasn't because of his strenght? Cope.
Sengoku was consistently put in the same tier as Garp by WB and Roger.
WB was laughing in Akainu face when blocked a Vulcanic rocks.
Was looking serious to Garp when he punched Marco.
Kizaru only injure Marco with seastone handcuff and Garp needed a punch to injure Marco so hard that he needed Bandages.
Marco was stopping Akainu Magma punches left and Right, when Garp needed one punch to made Marco flying back and be injured.
This a Prime Sakazuki and a Old Garp.
Imagine a Prime one, jesus.
Akainu block a giant ice rock and made vulcanic rocks out of them.