It wouldn’t really be a fight.

Royal Ghurka rifles

The Royal Ghurka rifles regiment is five companies of the elite of the elite. Recruited from Nepal and trained by the British, the Ghurkas are one of the finest light infantry regiments in all of warfare. They’re fast, numble, well armed, superbly trained and represent a credible adversary for anyone.

But.

You’re asking what would happen if five companies of elite light infantry went against the US Marine Corps. The entire British army has about 4,000 Ghurkas, the US Marine Corps has 160,000 servicemen and sport more combat aircraft than the Royal Air Force.

It’s a massacre. Ghurkas are brave, skilled and don’t go down easily. But they’re outnumbered 40:1 and pounded from sea, air and ground. Ghurkas succumb to the overwhelming everything, basically. It’s not without losses, but the end result is never in doubt.

Put an equal number of Ghurkas and Marines and give them equal support and the answer changes quite drastically. But as worded you’re pitting a small elite force against a much larger force of men who have above average training and more weapons than most military forces. There’s only so much that elite training and genetic adaptation to high altitudes can do.