I don't see the heorics in binding up an animal and then cutting his head off. That seems like something a POS Islamists would do.
Seems like an islamist would molest the goat, first... :^)
It might be a little more even if they engaged it in a headbutting contest, but I think I'd still put my money on the Gurkha.
I doubt it has anything to do with proving "heroics" -- more likely it's to demonstrate strength, speed, and technique with the blade. It's not easy to cleanly dispatch an animal (or human) with one stroke of a knife.
And carving a roast just wouldn't be the same.
It is a means of showing what would happen if he met an enemy. As in if he is able to do that to a goat'sneck with one slice he can do the same to a human. These guys are amazing with their kukris (ask the Japanese from WW2 or the Argentines from the Falklands about them. They were feared).
And anyways, they ate the goat. It is not as if they killed it and tossed it away. Every single animal eaten has to be killed, and i think a quick slice is better than slow cutting.
And this is totally different from Islamic kooks beheading some poor soul just for their murderous pleasure.
How do you think steaks make their way to your plate? :P
Would you rather see them cook it and eat it live?