At first I was a little perplexed by this lyric, but after attending a few Awa Odori dance festivals I came to understand it. For the Awa Odori, the number of dancers can range from several dozen to several hundred.
我本來很納悶，但當過幾次觀舞者後，終於領會了。成隊的舞者，少則幾十人，多則幾百人。