Agreed.
The proper way is to differentiate between hiring
- Hirelings:
Non risky tasks, relatively safe environment.
Example 1: Labourer.
Example 2: Cart Driver.
If the work require to be "far from home" for extended periods, then the pay should be better. If the work is relatively menial, but the
environment is not super safe, but in case of a battle the hireling is
expected to just take cover and avoid the fight, then he gets hazard pay.
As being a very different thing from hiring
- Henchmen:
Risky tasks, hazard pay, not dangerous every day, semi-dangerous environment, overland travel or patrol or sentry guard post.
Example 1: Caravan Guard.
Example 2: Man At Arms
Again, the duration of the job (how far from home and for how long),
the amount, intensity, and frequency of exposure to risks, and what the
NPC is expected to do in case of dangers, all affect the pay.
A good trick is to imagine an NPC setup without the PCs at all. Say soldiers in a little mercenary group, or a crew of pirates . They expect to be paid every day, not just "the days that they have to go fight". They also expect that the amount of danger is "reasonable". This means not being put into fights for days on end, with AMPLE downtime after each battle. They also expect to battle human-sized foes, not fantasy monsters. And they expect a share of the loot, too. And raiding and pillaging, too (or else, pay them better).
Now you want fighters that follow you into a dungeon, fighting SEVERAL times per day against TONS of high fantasy dangers.
Unless they are clearly weaker than the PCs, or extremely friendly (more like helpful companions than real "for hire" henchmen, then), the *strict bare minimum* they'll agree upon is a daily pay with hazard pay *AND ALSO* a full share of the loot (to their families if they die), albeit the PCs will typically get first choice. But a magical item's atual value is part of the loot so if the party of 5 finds a 35 gp magical dagger and 35 gp, this means 10 shares of 7 gp each, thus their 5 henchmen will get 7 gp and the party gets no coins and can split the dagger between themselves.
It's like having friends come help you when moving out: you pay them beer and pizza. Vs hiring professionals, you still give beer and pizza AND pay up the wazzoo too. Henchmen also expect to be treated fairly, not take more risks than the PCs (i.e. not willing to be the first ones to go front row), and not be more loyal than strictly necessary. A king might have his 20 men willing to rush into a deadly fight for him. After all they SWORE an oath to serve him. But mercenaries? They're in it for the money, and very few will accept "You work for free, until we find some loot to split up between ourselves fairly" nor will accept "You work for that fixed pay,and when we find nice loot, you won't get any big extra bonus".
Typically the henchmen are clearly weaker than the PCs, and thus get some fixed pay (which might vary by danger level off current area - overland travel to the dungeon is not the same as the days actually inside the dungeon) + say half a share.
Hazard Pay is for when you expect hopefully there probably won't be any fights, or maybe one, at worst two, and if there is a fight you expect hopefully it won't be too hard to win. That's like x2 to x5 normal "safe" pay. Dungeon Exploration however is more like "Extreme Hasard" pay and is at least 10x normal pay, if not more.
All of that is "negotiable", but ultimately the GM's goal is to make it so hiring "pros" to do the fight for them, will ultimately cost them more than what they themselves gain from being one of the adventurers. This is because "hiring" means having to pay some kind of premium, some extra. the only exceptions are when the NPC is in it by loyalty or super helpful or if doing the adventure aligns with their own goals. But if the NPC is mercerary-for-the-money, then a 5-men party of 4 PCs + either a 5th PC of an henchman-at-arms, it should be noticeably more economical for the first four PCs to get a 5th PC, than an NPC "same level" henchman. Same for the amount of actual risdks thae 56th man is going to take for therm: a Pc is a more loyal and reliable companion than a henchman.
And most of all, the GM should adjust the XPs. A party of 4 Level 1 PCs + 4 Level 1 henchmen, the situation is not "Just give the same XPs and split the XPs by 8 instead of by 4". Nope. The party suddenly counts as being a much stronger party i.e. as being a higher level party. So the encounter itself is now clearly worth LESS XPs, ssay, only 40 XPs instead of 80 XPs, and THEN the GM divides the XPs by 8 characters.
Basically, sure the fights are much easier. But the PCs have to go through a ***LOT*** more fights (in this example, 4 times as much!) to earn the same amount of XPs.
Basically they won't level up as much. As single henchman that has a motivation to be there "for story reasons", fine. But hiring on purpose as a way to make winning fights easy, ok if very short term, but long term it should be a losing proposition both in terms of money and EXPs.
In other words: if and only if the party seems too weak, add a single temporary companion, capable compared to other PCs, but not overshadowing any of them, that is 100% linked to the current adventure. Make sure he gets his fair share of the loot AMD of the EXPs. If possible make sure his goal will be reached within a single level. For example he wants too find the (MacGuffin) (that GM adds in last room of the 1st dungeon level), not make him stick around for the entire Adventure Path (which would basically become a DM PC).
Players that insist on hiring henchmen, typically do so around levels 2-5 when their PCs get rich enough to hire a few men-at-arms, but they aren't so high level that the men-at-arms suddenly start dying like so many useless flies every fight. Allow it, at say half a loot share per NPC henchman, and after a few NPCs "don't make it back", the party's reputation is damaged and nobody is willing to work for them except at extra pay and full loot share. After a few more "don't come back", their reptation is completely ruined and nobody want to be hired by them no matter what.
Typically if the GM points out that fights get slower the more NPCs there are in the party, AND makes swure to tell them that the XPs they got was say "your party is stronger by 2 soldiers, so the module say 80 XPs for that encounter... by a party of 4. With the soldiers in your group, this means that encounter is worth only 60 XPs instead." And then show how they would have already leveled up two game sessions ago. Thrust me they will drop the extra meat FAST, all by themselves.
