Re: A question about Shihonage!
4 directions is as good as 8 directions which really means ANY direction. I've also seen jujitsu folks start shihonage the same way and have it result in 4 different (devastating) endings.
When I thought driving power from thrusting from the hips was critical, I thought that the most helpful way to get beginners to think about it is to have nage be as SW corner, and uke be at the NW corner. Then as nage thrusts and then follows in a NE direction, uke lifts themselves up and starts pivoting (which nage continues to follow) such that they (the uke) start to fall in a SE direction to the SE corner, landing the pivoted nage in the NE corner. So the 4 directions are nage orientation from facing NE to SW (and floor), and uke orientation from facing SE to NW (and ceiling).
Now, I would say I do something entirely different, which does not depend on driving from hips or following (but I still think following people into themselves is a valuable skill to learn).