Controlled demolitions rarely start at the top -- the goal is usually to have the structure grind against an immovable object (the ground) as low as possible. This controls the debris field, and this means the most momentum due to gravity right from the beginning.
In a four-story structure, however, the thing is so low that it really makes little difference. The gravitational potential will be relatively small.
If you follow the work of Bazant and Zhou, you will accept that a single floor demolished high in a WTC Tower would lead to total collapse of the Tower. This is not in dispute (except most conspiracy-minded folk reject their work, which makes the CD hypothesis much harder to support). Such a collapse woud not, however, resemble what we saw for numerous reasons, not the least of which are the lack of explosive sounds, how the explosives survived impact and fire, how they were planted in the first place, or the gradual deterioration of both structures.
Nothing to see here, folks.