|Sum of Misunderstandings|
Sum of Misunderstandings
Each time a player character sends out a non-player character on an errand, the referee should carefully take note of what is asked, and determine how it is interpreted and applied.
Maybe the characters don't share the same language, maybe the NPC isn't very bright, most likely the player's request was ambiguous, poorly formulated. Or the player character has low charisma or on the contrary, it is too high and has unexpected effects on the other character.
There is a role-playing opportunity, the player ordering the NPC and ensuring there are no misunderstandings. Some experienced players might require of the NPC they repeat their instructions, carefully rephrasing important details.
"Okay, you and your brother are going to hide behind the wattle fence there. As soon as the enemy crosses the line between the norther corner and the goat shack, you rain arrows on them" — "Got it, we hide behind the fence and we shoot at anything we see" — "Well, not exactly, listen again, ...".
Also, remember that it's sword and sorcery, not sword and mobile phone — once the NPCs are running on their errands, there's probably no way to contact them until they come back. More planning is necessary, unless your caster has a spell in up their sleeves, there is no "let's call them and tell them to buy flour on the way back".
Maybe it is too cruel and the referee should stick to ellipsis and limit randomness to setting and combats, preserving the moving parts of plans from misunderstandings. After all, real life is full of such friction and, for the enjoyment of the game, it would be better to keep them out and forget them while at the table.