Are they using Gaelic or Welsh? Could have Aehren do something. Also, backwater barbarians, Lady Vekk? Aehren is standing right there...
Sounds something like Gaelic with a sprinkle of Old High German for fun more or less.
And take no offense by the casual racism! Aehren is obviously an educated man of the Empire. It is her more akin to calling them redneck hicks in reference to their location of origin not to their entire people, and how they are acting.
I didn't really go into this but the West and North of the Empire are generally filled with more peasantry and farmers that held very close to their barbarian roots. While those in the South and East mostly because of a higher Qalini population their during the time of the Magocracy are consider more "civilized" with an dialect of common much closer to that of old Qalini nobles than their barbarian forebears. So kind of like the difference between the accent of a man from Sloane Square in London aka decidedly posh and upper class compared to Cockney. Since the peasentry kept a lot of the speech patterns from their own language as seen with the Captain in their common dialect. Since they rarely dealt with the Qalini so they had litle need to learn common and the common they did learn was corrupted through various other sources. While Southern and Easterns and those of nobility like Aehren would speak in this dignified accent that the Qalini a very large presence in that area for hundreds of years sort of implanted onto them as time went on, so they sound normalish.
Qalini common sounds normal (Or we've been typing it like standard English to make it easier) due to the Qalini Magocracy's terribly large influence when they were still around as the largest dominate force in the known world, their dialect became the standard trade language especially in the Free Cities as they used to all be under Qalini occupation.(A tradition which holds today because inventing a new language would be a lot of work to replace something that already works since mostly everyone knew the Qalini variant of common anyway.) Though now a days the Sadia dialect of common also holds some popularity due to their position as the new trading power with it heard mostly among merchants and sailors. Though of course most of the the Empire's nobility still knows how to speak Niratremi they just don't because they think it makes them sound like wait for it.... backwater barbarians.
So in short Nobles and Eastern/Southerns speak mostly a variant of Qalini Common very similar to that of the rest of the Free Cities. (Since they are mostly Nobles, Merchants and others of high standing in those parts.
In the West closer to the Imperium, and the North they generally speak Niratremi among themselves (more of the working class and the peasntry) and will only speak common among outsiders and their common is a corrupted variant using many loan words from Niratremi as well as soundly distinctly different and much closer to the peasantry of the Imperium's Eastern Border since they both share common ancestors.
Sorry for the boring linguistic lesson but I felt it could be useful to somebody, somewhere lol.