The esoteric part comes into play at the Step where you need to understand how to use the mind since we all do that differently. Once that is accomplished, then a logical step by step approach is easily implemented after establishment of your personal mental intent baseline, etc.
As for being short, you must be an expert at getting under someone and doing aiki-agae
i think you hit on the right spot. everyone's mind works differently, i.e. their body responses different as well. this makes learning aiki different for everyone. there is a gross baseline of aiki training that everyone could train. after that, it's all personal.
couldn't get under Sigman. shorter than him and squatting very low and he didn't change his body posture one bit. methink, if i lay on the floor, he probably could still get under me without changing his body posture. it was an eye opener to me. can you imagine what that means to judo/jujutsu folks where you can get under someone without even change your body posture?