Purchasing new units

[wizaerd]

So here I was working my way around the map, fighting battles, enjoying myself... And eventually ran out of swordsmen. I went back to the castle, and there were no swordmen available. They system doesn't replenish troops, so how do people build consistent armies? While I'm sure there are more powerful troops available eventually, for where I'm at, I really like the swordsmen, but there are no more.

[Hunter]

Hey there wizaerd,
Unfortunately if they ran out, they ran out. You can check around the different zones around your location to see if some other place have them (other castles on the begging continent generally will, from my experience). In addition, once you finish the Cage, Box demon thingy, like second quest in the main quest line, the swordsman will become unlimited in the main castle, I think, I am pretty sure.

[DanTheTimid]

Like Hunter said, over the course of the game as you complete quests the unit inventories towns and castles have often change. In the case of the main castle, it continually gets more and better units as you complete the main quests, and older units often return in infinite numbers. I'm not 100% sure when swordsman become unlimited, but I know for sure they do (I'm still using them well into the game primarily because they're so easy and cheap to replenish).

Its worth noting that
A) You're going to find all sorts of troops all over the world. I can't give you specifics (as they're random what you'll get in each play through) but in general if you run out of one troop, theres some other creature you can hire to replace them.
B) That said, because of the finite nature of some troops (and nearly all troops in the early stages of the game) its often best to spend the early game avoiding battles when possible and just picking up loot and leadership. Once your items are better and you're troops sizes are better you can go back to those enemies you avoided earlier and take them out with few if any casualties at all. In this way the King's Bounty games have always differed greatly from the traditional rpgs where you actually want to fight as much as possible as soon as possible to get stronger.
C) If your started as a Paladin you'll get a resurrection spell right from the get go, if not it might take a little bit/require so luck, but I believe you'll eventually get the resurrection spell. Said spell lets you revive lost troops in battle, negating casualties. Guaranteed early access to this spell is one of the reasons many consider Paladin the easiest early game class (even though some consider them the worst in the late game).
D) Later in the game, unless you get really unlucky, you should eventually get a spell called Sacrifice. Said spell will allow you to increase the number of troops in any group, thus even if you lose a ton of a specific rare unit in the early game, you can still "refill" them later through sacrificing infinite spawn units to it (again, its why I still keep swordsman around).

So yeah, don't fret too much, but definitely keep in mind that King's Bounty games aren't your typical rpg, you generally want to explore/loot maps as best you can first, then once buffed up go back and start actually fighting. I'd never played a King's Bounty game before this one so it was a lesson I also learned the hard way when I first started, but I recovered from early causalities just fine so you probably can too.