What's the logic behind the numbering of our Destroyer Divisions -poi?

Main Character

Heroine

Protagonist

Kai ni

Good question ♪ There is a proper meaning behind it

DesDivs 1-10 Yokosuka Naval Base (Chuubu Region and northwards Hokkaido Region)

Each DesDiv's number will give you a sense of where the destroyer division's home base is located. (The crews are also gathered from the general region of the naval base)

DesDivs 11-20 Kure Naval Base (Coastal regions of Honshu along the Seto Inland Sea, and coastal regions of Yamaguchi/Hyogo along the Sea of Japan) The area of Hyogo prefecture along the Sea of Japan seems to be under the jurisdiction of Maizuru Naval Base, according to this map though...

DesDivs 21-30 Sasebo Naval Base (Shikoku and Kyushu regions) Shikoku is clearly under the jurisdiction of Kure on the map, and so is eastern Kyushu...

DesDivs 31-40 Maizuru Naval Base (Coastal regions along the Sea of Japan, including Kyoto and Yamagata)

Poi-

Both the home base and division number might change, so let's be careful shall we?