This reminds me of Foundation, or espionage. Secretly assign multiple people to a task to reap the benefits. That doesn't mean assigning a group of people to a task would perform worse. There is a difference between multiple people working alone and multiple people working together.
From the article:
"That study, led by graduate student Bethany Burum, started with a simple experiment: Burum placed two individuals in a room and had them spend a few minutes getting to know each other. They then sat back to back, each facing a computer screen the other could not see. In some cases they were told they’d both be doing the same task, in other cases they were told they’d be doing different things. The computer screen scrolled through a set of drawings of common objects, such as a guitar, a clock, and a log. A few days later the participants returned and were asked to recall which drawings they’d been shown. Burum found that the participants who had been told the person behind them was doing a different task — namely, identifying sounds rather than looking at pictures — did a better job of remembering the pictures. In other words, they formed more solid memories when they believed they were the only ones doing the task."
The article goes on to suggest that participants expended focus on the other participants rather than on the images.
But fair warning, this is a pop science article critiquing society. I need to follow up on the above study.