I believe that most traders (<10K USD) are irrelevant to the manipulator other than as some kind of probabilistic amplifier. The 1k, 5k, 10k USD, etc bulk walls are often meant for other manipulators. If this wasn't the case, it would make more sense to give the impression of multiple bids/asks throughout the spread. This is especially true when the big walls get nearer each other than 1% (mt gox fees) of the current value.
I know almost nothing about trading psychology or technology, tell me why I'm wrong.