Thing is, Armadillo's trying to construct a relatively large spacecraft that can make a controlled descent and landing on the surface of the moon
. You can strap some model rocket engines to a gyroscope and make it hover for a few seconds, but that's a far cry from a functional landing craft (or, for that matter, a functional Dragon space capsule).
There's also the fact that the multiple kill vehicle has effectively been scrapped because they couldn't get the smaller projectiles to synch up properly. Hell, they can barely get the one-shot version to work correctly; according to some reports, it doesn't work at all
. But that's beside the point, because it's not designed to actually shoot down incoming ICBMs, it's designed to deter America's nuclear-armed enemies (whoever the hell that's supposed to be) from launching missiles at us.