"Dancing is two people dancing as one. If you roll from the heel to the ball and your partner rolls from the toe to the heel what could be more together than that."
Yes, there's two phases in the position of the weight - heel, then ball.
But the placement of the foot is almost whole foot - it's heel, directly followed by the ball of foot contacting the floor, some would even opinion immediately so.
Needless to say this is not symmetric with the backwards action - probably because our knees only bend in one direction.
And the fundamental principle remains: delaying your arrival will not give you the right timing, instead it will just give you an artifical stuck-between-feet interlude. To get the right timing you have to learn to draw out the end of the preceding step, especially when we have a lowering step preceding a heel lead, we have to not finish the lowering step too fast.