NB, I love you, this has nothing to do with power levels, chakra reserves or battle prowess....
I get what you mean OP. Right back in part 1 Kishi drew a character personality chart and Kiba and Naruto were right beside each other. But from then Naruto developed and matured due to the hardships he faced and the losses he experienced. Kiba on the other hand didn't go through the same stuff so didn't mature. Basically narutos character was moved along because he is a main character, whilst Kiba's didn't because Kishi forgot team 8 exists. Basically Kiba is still part 1 naruto when he was easily provoked and wanted everyones attention (they both want to be hokage as well).