So place names change over time according to the official census? And people actually switch the name they use? How brutal are the punishments for using the older name to make that work? Or maybe there is a ramped up Mass Suggestion spell after every census to get people to change what they call a place? Or does the Empire accept that this is for official use only and most people stick to traditional names?
The Empire, of which I am speaking, knew in fact two periods of great prosperity, from 1900 NE uptill 2350 NE and from 2785 NE uptill 3049 NE. In the Classical Empire and the Second Empire, there were no punishments for ordinary people using the old names. The decision was mostly taken in Nasairian (the fifth month of the year). E.g. Amvaiardan was changed into Amvaimuros on the 15th Nasairian 2854 NE, but the message had to be brought to Amvaimuros, and that took 5 days (Bedbasiravan to Amvaimuros was about 450 miles). The local Counsil had to change all the plates mentioning Amvaiardan, all the new documants had to mention the new name, in older documents Amvaimuros was added to avoid ambiguity. There were only punishments for official instances, who didn't use the official name. The offender had to pay a UD 150 fine. However, if the old name was used in folklore or an other non-official instance, the Empire allowed it.
I don't really use name convention but the name of the same culture are more similar. Unless you choose you word carefully, I found that names that descibe the place don't do well in a fantasy world. But it might be ok for you if you want something more historically acurate.
Try to find something that sound great and that reflect the spirit of the place. Having memorable names is the most important thing. Of course not all names should be memorable.
So what I usually do when I don't have ideas is to find something like an object, flower, color, plant... that is linked to the place and just change the letters in the word a little bit. Just enough to sound unique.
You can also modify words from other languages but it's betgte to have some understanding of it to avoid being a fool to native speekers.