How many henchmen and the like that showed up in my pre 3.5 games varied greatly between games. Some we had none, while others our "party" was very close to 50 people. Typically we always tried for around 8 PCs, with the DM playing one or people running multiples if needed. Even when just NPCs, it seemed there was enough people and most roles were duplicated with two fighters, two spell casters, two theives, etc.
With 3.5, the NPCs disappeared and party size shrank to 4 or 5. That just really doesn't make sence, especially at lower levels. One person goes down and you're out a role most likely. eg Cleric goes down and no more healing. Too many times I've said to myself, why are just the four of us cleaning out this dungeon in several trips, when with just a few hirelings we could probably clean it out easier in a night?