Garran: You may have hit a wraparound issue with the spawn system, but I don't have the old lists to check on whether that's possible. I do know that you want to make sure you're at least level 6 before entering.
If you still have the save game then the best option would be to leave the entire area (head out to the road and find a hidden corner) and camp for just over 24 hours (three full periods plus a small bit of a fourth) to see if that resets the spawns in the city.
One other thing to keep in mind: the creatures generally won't follow you into buildings UNLESS they've already engaged, so if you see a group coming you can get inside somewhere and out of immediate LoS of the doorway to lose them. (Pretty much every occupied location in Arnika other than Antone's shop lets you do this - and Antone's will if you go through a door.
Likewise, they can't open doors, so nipping inside somewhere and slamming a door in their face is a good way to avoid trouble.
There is a list at Flamestryke's Wizardry 8 Website: [url=]http://www.zimlab.com/wizardry/flamestryke/wizardry8/flamestrykes_w8.html[/url]
This is probably really a wraparound: Instead of Savant Gunners (Levels 5,7,8,9) appearing without any other Monsters, you got yourself probably Savant Slashers (Levels 15,19,21,23), which appear with Savant Gunners (100% chance of appearing, 3-5 Gunners)
There is, however, another possibilty: Due to some bug or a quest (meeting the Dark savant and then fighting him) firing at the wrong place and time. His summoned Savant Henchmen also can have Level 21 (Levels 12,15,19,21)
They are the only Savant with a Level 21, so it must be one of both