On the Use of Henchmen in OSR Games
From what I've read online, our experience was not unique. However, I've also seen for many groups henchmen were an important component of the early game and the 1st edition Dungeon Masters Guide bears this out, with considerable space dedicated to the acquisition and loyalty of henchmen.
In our AS&SH game, one of the players had two characters, both of whom had high Charisma scores. He decided to use some of his starting cash to hire some mercenaries. It wound up being an extremely good investment - giving the party additional firepower while at the same time giving the monsters additional targets to aim for. I suspect should the henchmen survive up to the point where the characters make it to second level, I might allow the henchmen to gain a little bit of experience and reach 1st level, with an eye towards allowing them to lag behind the main characters but be available as standby PCs should some of them meet unfortunate ends. And of course, that assumes the henchmen survive as well, something that is not a given.
One thing I'm a little curious about is what the inspiration for henchmen in the original game was. Having descended from wargaming, I can imagine part of it is a leftover from that. In fiction, I can't think of many scenarios where henchmen played an important role for the protagonists - I do seem to recall some Lankhmar stories where Fafhrd and Grey Mouser had some mercenaries but I can't think of much else - though I've also not read the entire Appendix N canon...