Do you know what your militaries carry? I mean actually carry - not just “chain mail, spear, shield”. We came out with An Army’s Arms a while back, and to be honest, they didn’t sell well. Each book is a detailed description of an army and their gear. I mean - really detailed. Well, that didn’t work the way we wanted, so we loaded up A Baker’s Dozen Tribes with a lot of gear notes. That did better, but with sales of Army’s Arms low, we didn’t publish the others we were preparing.
But back to the question - Do you know what they carry? Does the army issue each soldier with his kit? Do you know what’s in it? In order to know, you need to know how they’re fed. If there is a chuck wagon that travels with each battalion, then they need a lot less than if each squad cooks for itself. The point today isn’t really do you know what they have, but more to the point, Do you know who made it? If you think about all the stuff a soldier normally carries, even if it is just the combat system relevant stuff (armor and weaponry), who made it is very important. If you have an army of 6,000 swordsmen in scale mail, someone had to make all that. You need a lot more than a couple of blacksmiths to bang out 6,000 swords. Worse yet, if they all carry bows, then you need 6,000 bows and probably 120,000 arrows - not counting the ones they lose practicing. Who is making all that?
This is the way I build my worlds - I ask myself questions like this and then develop the answers. Depending on the place the army exists, there might be a weapons factory. If there isn’t, then there are a series of weapon crafters and armorers - and they might be of different skills. Now very few of my soldiers carry swords, but you still need to figure out who crafted their spears, shields and armor, even if it is studded leather. By figuring out some of the army of smiths who were working for the military, you can probably figure out who the player characters would go to for theirs. It gives those guys a reason for existing, not just waiting on the couple of adventuring parties wandering around the city.
I love the Three Musketeers - I won’t get into it, because this is already too long, but I love A. Dumas. One scene from the original book that I love is when they have to go to war. They’re told to get their stuff together and show up in a few days ready to march. Well, the heroes have squandered their pay on booze, partying and women. They have no funds to go out and buy war horses, uniforms, etc. They wind up selling a diamond to get the money, but the concept that the officers and nobles had to supply their own gear from the pay they received (and that they typically didn’t unless forced) entertains me. In that world, there must have been a host of tailors for military cloaks and uniforms, horse traders with steeds from nags to the finest, weapon smiths capable of etching coats of arms and other insignia, saddle makers, bag makers, scabbard makers, etc. etc. etc. No - You don’t need to make up each and every one of these businesses! You could, but I wouldn’t suggest it, unless you have players who love to role-play shopping. But you do need to have a handle on the fact that these folks exist and need to have shops in your world. I’ll go so far as to say that you ought to have a portion of the city (near the garrisons) where a soldier could find all these shops within a few blocks of each other - a mercenaries’ mall.
Maybe some of you have your worlds developed to this point, but I’m guessing few do. Maybe you just work off a price list - chances are it isn’t enough. I strongly suggest that you find the happy medium - a place where your players believe that you have nearly everything developed, but you have not bothered to work on anything that is never used. Utopia, right? But beware - get too detailed, and you won’t be able to remember it all anyway. Then you wind up stumbling during game sessions while you check your notes on that guy who sells the silvered armor.