I agree with that point! I think having 4 persons on a single computer leads to great inefficiency and a means of dragging projects behind. However, the adopters of mop programming claim to have eliminated the need for having code reviews as a separate process on the development lifecycle.
That's a point I can agree with. I would prefer to have 2 pair programming groups working on 2 separate computers than a single group of 4 working on a single computer.