I somehow little bit tinged on why those 4 are closer with each other rather than the rest of their sister (Ayanami-class)

Added tag for the Naka poster on the headboard of the lower left bunk.

Strela said:

I somehow little bit tinged on why those 4 are closer with each other rather than the rest of their sister (Ayanami-class)

The same reason why the Shiratsuyu class are usually seen without Samidare and Suzukaze: drawn by different artists. There's also the fact that the 4 ships are actually under the same unit.

Strela said:

I somehow little bit tinged on why those 4 are closer with each other rather than the rest of their sister (Ayanami-class)

Because their isn't any particular connection between most of them. 'Sister ships' are really just a vague often arbitrary grouping of roughly similar units, but units of the same type in a large class may well never operate together or even see each other. It's utterly logically that they would tend to congregate with those they knew and often worked with.

Strela said:

I somehow little bit tinged on why those 4 are closer with each other rather than the rest of their sister (Ayanami-class)

Too many Foobookie-classes*. And too many members within the same subclass as well, excepting 6thDesDiv. Girls done by different artists also look a bit strange (i.e. theme-breaking) when grouped together. Murakumo is the most prominent example.

(Remember, Ayanami-'class' is Fubuki II/Special Type II, and Akatsuki-'class' is Fubuki III/Special Type III)

On a related issue, too many Kagerou-classes.

Akebono, do you even forget the ghost like skill admiral can do popping out of nowhere?