| Nargrakhan |
I believe the intention is only Cohorts gain XP, with certain limitations, as per the Leadership feat. Followers do not gain XP. Hirelings and Henchmen are not Cohorts.
Also, Hirelings and Henchmen are typically considered GM controlled NPC's. If they need to gain a level for whatever purpose, then it happens at the GM's prerogative... as would the skill and feat selection of said NPC. XP would be irrelevant.
Having a custom tailored NPC that gains strength over time (with GM oversight and approval) is again, a Cohort thing.
| Tangent101 |
The Leadership feat has information on this.
Henchmen are known as Cohorts in Pathfinder. They can gain XPs using an alchemical chart involving higher mathematics and the sacrifice of a chicken to determine how many XPs they get (but basically comes down to "your Cohort will gain sufficient XPs to be less than a level under you in all likelihood but the rules only allow him or her to be two levels back"). Followers/Hirelings do not gain XPs and never level up (though personally I'm going to fudge that for one player as her hirelings have a Background Story reason behind being with her, so as her Leadership score goes up, it makes sense for them to slowly gain levels even as they'll never be truly effective in combat).
| Nargrakhan |
Please correct me if I'm wrong, but there's nothing that says Hirelings don't gain XP. There's also nothing that says Hirelings do gain XP. Hirelings are NPC's entirely under the GM's purview. They gain and/or do not gain at his whim or as the campaign requires.
On a minor note: Hirelings are not Followers. A PC can have a Cohort and max out her number of Followers, but still be able to acquire a legion of Hirelings.
Personally, I tend to view that NPC's gain via the Leadership feat are loyal to the PC out of a sense of duty, friendship, shared ideals, etc. If treated fairly and with respect, they will walk with the PC through the Gates of Hell itself. I also let the player have weighted input on their stats and gear (more so for the Cohort than the Followers).
Hirelings are just NPC's (usually) gained via money or a favor. They're in it for whatever task they were paid to do, but really not much else. The classical person who'd walk out and say, "it's not in my contract," when the task wasn't. I let the PC make a request for whatever area of competence the Hireling has (an Adept that can cast Heal, an Expert who can forge a masterwork weapon), since that's why he's getting hired, but the stats are entirely mine and mine alone to decide (thus rendering the XP thing moot).