Perhaps some projects can be broken down into component, but there is a point that they can't anymore. If it takes 5 people 5 months, then perhaps 25 people can get it done in 1 month. But there are limits. I don't think anyone who has ever worked on a project believes that you can then put 750 people on most projects and get them done in a day. Sure, its possible if the task is trivial, but most aren't.