There is a saying in golf about an iron shot that goes “thin to win”. In duffer lore it means the golfer almost missed the shot but might get away with it but in the professional world it means a shot that is low, nipped from the grass and has a lot of back spin to stop the ball on the mark.
One is a good result and the other is not such a good result. Professionals using thin shots win in golf and professionals in noise control should do just the opposite. Thin typically provides none of the characteristics needed in a sound control mat; resilience, airspace and some thickness.
Thin mats create a vibration break but are ineffective at the most problematic frequencies – the low frequencies. In wood frame the low frequencies are always the difficult culprit. In concrete this story might be more of a winner but thicker always is better in noise control. Thin to lose would be the result a professional would want to avoid.