In old school Advanced Dungeons & Dragons it is often advisable to travel with a large retinue of companions, servants, henchmen and other support personnel to increase the chance of a successful endeavor. Especially on long journeys away from a civilized home base, this support structure is critical and invaluable.
Perhaps no other TSR published module of the AD&D 1st Edition era exemplifies the need for a whole caravan of retainers than D1-2 Descent into the Depths of the Earth. This adventure is a combination of two earlier monochrome modules D1 Descent into the Depths of the Earth and D2 Shrine of the Kuo-Toa (which was my Day 2 Module Challenge pick). This extended trek into the Depths of the Earth (Underdark for those younger gamers) sees adventurers travelling through miles of twisting tunnels teeming with dangerous subterranean flora and fauna.
For such an excursion, only a well equipped party with lots of support will fare well unless many important skills and abilities are covered by the party members. Arrows will inevitably run out unless more can be created, weapons will break or need skilled repair. Carts and beasts of burden will need tending while the adventurers are off exploring. Even with a ranger in the party it will be difficult to find food and potable water, since it is unlikely that such a character is native to or familiar with the environment. The logistics alone are daunting, and undoubtedly not all retainers, pack animals or supplies will survive entirely unmolested for the length of the journey.
When I ran this adventure in the early 1980s for my group, which then was rather large by most standards, there were 8 players, the PCs numbered a dozen. The party had a few carts, each pulled by a mule (I seem to remember more than one of those eventually ended up pulled by subterranean lizards). Most of the characters had at least one henchman who often filled a secondary role covered primarily by that PC, or another in the party. There were also a few hirelings to cover more logistical functions. There were teamsters to drive the carts, a sage whose collection of relevant source materials took up a fair portion of one of the carts. The ranger was a skilled bowyer/fletcher, and the paladin kept all the edged weapons in good repair. The more mundane functions were covered by PCs mostly, though the sage was also quite a good cook.
I fondly remember this adventure because it ended up being so much fun. What modern play-styles often miss, in my humble opinion, is the adventure and excitement that a random encounter ghast raid on the retainers can be!