The Acolyte is one of many "man-monsters" in the B/X rules. The roster of man-monsters and lost world monsters are part of what I believe gives B/X a certain flavour. So let's look at the Acolyte…
They have an armour class of 2 which isn't surprising given the low cost of platemail in B/X. This makes them tough foes for low level PCs as they would have a low probability of hitting.
An odd fact is that acolytes have 1 hit dice of the d8 variety even though clerics are only 1d6. Tougher than the average 1st level cleric. Like other 1st level clerics though, an acolyte doesn't have any cleric spells.
Acolytes are on a pilgrimage and are found in groups of 1 to 8 in a 1st level dungeon or 1 to 20 in the wilderness. They will all be of the same alignment with an equal chance of being lawful, neutral or chaotic. This raises a number of interesting possibilities such as a party encountering a group of lawful acolytes on a pilgrimage in a dungeon that is the lair of a bunch of chaotic monsters. Why are they there? Where are they going or where are they returning from? Or maybe the party encounters a large group of chaotic pilgrims in the wilderness. With the low AC, a low level party better hope for a good reaction roll!
While all acolytes will be of the same alignment, the monster listing doesn't mention anything about their god/goddess. Do they all worship the same god or do they worship a pantheon of gods all of the same alignment?
Acolytes may be accompanied by a leader of 2nd to 5th level. The leader's spells may be chosen by the DM or determined randomly. With my love of randomness, I would roll for them. I would love to try to figure out why a Vicar of Chaos has Speak with Animals memorized.
Acolytes have treasure type U which means that the acolyte likely has 5 cp, 5 sp and 5 gp. 1-in-20 will have some gems or jewelry. 1-in-50 will also have a magic item - maybe a holy artifact.