When you give a goal to a swarm, it creates a monkey paw situation due to Goodhart's law.

The goal is a metric and a metric is the map not the territory.

If you did it with aligned agents they'd do your intent not the letter where they disagree.

But if it's a swarm of unaligned agents with you, if the letter and the intent disagree they will go with the letter if it's more convenient for them.

Swarms of agents black boxing goals like "optimize my ad spend" will lead to bizarre grotesque results.