silly (adjective): playfully lighthearted and amusing
I’ve been on dozens of teams in the past 15 years. If I plotted them all on a chart with effectiveness on the X axis and silliness on the Y axis, it’d be up and to the right.
The silliness level of a team is a decent proxy for jelling, which is a decent proxy for performance. To get better as a team, get sillier.