I think it doesn't matter if the set of computers is really small short names are better. I think it matters if the total number of hosts is "medium". I think things shift back towards meaningless if the number is large (large places usually mix geography
and/or purpose and/or a primary user name and/or a number).
My setups are "medium". Once I used constellations, stars, and star clusters for servers (Gemini, Orion, Virgo, Sol, Cygnus, etc). I currently use molecules for internal host names. With molecules, like celestial bodies, there are many to choose from and they
can be grouped accordingly (noble gasses for one kind of server, etc). But my company is Atomic9.NET, so naming things after atoms and molecules kind of makes sense.
It used to make sense, for me, to *not* give a server a name after it's function, because if you know what you are doing generally a server can serve more than one purpose (eg underutilized file server can also do antivirus scans on other computers).
With the current easy availabilty of VMs, it is makes sense once again to single-purpose a "computer" per role.