Maletrain: At the right speed, yes. Due to larger masses and longer springs, the oscillation frequency is lower than in N scale, but at the right speed, they will oscillate.
Another problem, unrelated to couplers, turned up in the 1970s. The new 100-ton grain hoppers kept falling over. It turned out that the truck centers were 39 feet apart, the same as the length of a piece of bolted rail. Since the joints were staggered, both trucks on one side would hit a low spot at the same, then both on the other side, and so on. At low speeds, typical of poorly maintained branch lines, the truck springs would hit their "harmonic frequency", and the rocking would keep growing until the car fell over!
