"I put the and count after beat three at the begining of STEP 1. If you wish step 1 to land squarely on beat 1, then the part of step 1 that takes place before the foot lands (which is about half of the step!) must take place before beat one... which is to say, during the later portion of beat three."
You could subdivide the beat down to whatever level you want. Whether it's 1, 2, 3. or 1 &, 2 &, 3 &. or 1 e & a, 2 e & a, 3 e & a. Your focus should be on when your step is considered to have been taken or when your foot is planted (not when to start to move your foot to take the step which I think is why the desciption for when to lower is vague or not excruciatingly precise) and that is right smack on the beat not on the 'e', the '&', or the 'a' of a beat. Otherwise, it would be dam near imposible to tell if you're dancing to the tempo of the music.