As a young gamer, which I no longer am, I was entranced by the extensive ironmongery list offered in 5th Edition Tunnels & Trolls, and I still find it entertaining. As I grew more aware of history and various cultures, I saw that the weapons list taken as a whole was an Anachronism Stew: a first or second century pilum and gladius might appear in the same adventure with a 16th century zwiehander; western european broadswords share the stage with subcontinental hardware like the madu, pata, katar and kukri. A berzerker warrior (11th century Northern European) might take time after slaughtering an orc (20th century high fantasy) to clean the gore off his grand shamsheer (18th century Persian) and slather on a new coat of curare (indigenous South America).
But I like all that stuff, so I'm inclined to make Ardis a world where that can happen.
Everything on the central part of the main continent south of the Teeth of the Gods is modeled on 16th-17th century Persia and India; it's the heart of civilization in Ardis and so all those wacky, curvy swords and knives tend to crop up in all the big cities.
Vladria gets its model from 15th and 16th century central and eastern Europe: Lots of the halberds and elaborate plate armor crop up there.
Ys, and the rest of the extreme northlands, are an unabashed melange of 8th to 13th century Scandinavia. I like having hairy berzerk northlanders, I read too much Fritz Leiber not to (hence my albeit unconscious robbing of The Trollstep Mountains; they're too good a name for the place to change it now.)
For the southwestern part of the main continent, Galiana, I'm thinking of drawing heavily on the 15th century Mediterranean: Italy, Spain, southern France: touchy swordsmen.
Traditionally "Roman" weapons like the gladius and pilum will be found either as ancient artifacts or in the hands of monstrous armies: goblins, orcs, and whatever else comes boiling up from underground.