我下放農村時學會的 一 驫 三馬, 馬年的回憶。
If 馬 symbolizes a star, 萬馬奔騰 would symbolize a galaxy or constellation in one spot physically or visually, equavilent to 驫; therefore, 萬驫奔騰 would symbolize the whole universe filled with billions of galaxies consisting billions of stars, so you can imagine its scale and implications.
If this confuses you, it's all my fault, not yours :)