I understand your dad's feelings about ROK troops. Also, the Gurkhas were by far the most feared killing machine that could be unleashed on anyone. The Chinese had no problem charging head long into a devastating defense but at night they feared a visit from the Gurkhas. I don't know if he told you why, but they were silent killers. I knew guys in Nam who served in Korea, and they said they weren't someone you tangled with.
You want to know the real sobering thought on this subject? At any given time, there are roughly a couple dozen Gurkhas serving in the SAS. Can you imagine Gurkhas with SAS training?? Whatever the problem (wherever the problem) just send a squad of them, and it'll get fixed.
I recently read that the US uses retired Gurkha soldiers as security personnel at embassies and naval bases in areas where security is especially precarious.
Their motto is "It is better to die than be a coward," and the Japanese were utterly terrified of them. Japanese infantry doctrine emphasized ranged combat and rapid, massed assaults, and Gurkhas were lethal close-range, hand to hand fighters - especially with that vicious curved knife I can't recall the name of. They were also masters of psychological warfare; they would often creep into Japabese positions late at night, and tie the sleeping Japanese soldiers' shoelaces together, or cut the laces off their boots with their razor sharp knife.
The Japanese would often sleep 2 men in a foxhole; one man on watch while the other slept. The sleeping man would sometimes wake up to find his partner's throat cut. Message sent, message received.
There was one Gurkha who singlehandedly held off an attack of roughly 200 Japanese; they tried throwing several grenades; but he kept scooping them up and throwing them back, until one blew his hand off.
So for the rest of the night, he had only his left hand to load his rifle and shoot it. By morning, he had inflicted roughly 30% casualtries, about half of them KIA.
There's a story (probably apocryphal) that Gurkhas in Europe were asked to volunteer for a very dangerous mission; they would be dropped behind German lines from an airplane, conduct their mission, and then sneak back out before morning. When the officer asked volunteers to step forward, he was surprised that barely half of them stepped up. He whispered to their officer, "I thought your men were supposed to be unusually brave". Their lieutenant whispered back, "You forgot to tell them they'd have parachutes".