It seems my words were not enough.
In the novel, "The Red guards Fleet" isn't used as a name of an honor guard group, but as the generic name of the whole PRJ Navy. That's strange naming I think, but anyway they are called so in the book.
And this is out of description in the book, I think 日本赤衛艦隊 is more official as you said. Through using this name, I think PRJ can claim that they are "the real Japan" against SJ and to the world.
About the names, you pointed again that I didn't realize. These names are from that PRJ wanted to do, especially 解放 and 統一 were. PRJ was a piece of the house divided, so as you pointed, these names must have helped to improve morale.
The phrase "stupid" might be mistake. RGF in the novel wouldn't think such about this issue.
This point is in OTL.
As a premise, this novel was written for Japanese people. On the other hand, modern Japanese navies i.e. both of IJN and JMSDF in OTL, never named their vessels from the prominent figures. For this reason, many Japanese reader were having a prejudice that "ships named from people's name aren't Japanese warships". So despite it's an AH, readers feel something strange about the appearance of Japanese warships with people's names. That's why I said if NJ ships~ etc.
On the contrary, there are works that emphasized "This timeline isn't OTL" by Japanese carriers named after historical figures appear. Whatever, in their timeline, the reason was just lack of the place or people, as you suggested.