First off, as a kendoka I'm talking out my ass when it comes to real sword techniques. This is idle speculation on teh interwebz here. The main problem that I can think of with nidan waza is that if a real sword connects on the first target, there's going to be some trouble getting it to the second target. The most common is kote-men, where as kendoka we typically rely on the kensen popping up off the kote to carry on into the men. With a real sword, you'd have to either miss (ie the kote is a feint, not an attack) or clear the sword from the kote by either yanking it or driving it through. All of those options are much different than a kendo kote-men, which as I've said is pretty shinai/bogu reliant. I'm not sure why hiki-waza wouldn't work.