This has been observed repeatedly, Fred Brooks wrote a whole book about it. Everyone says they've read and agree with "The Mythical Man Month" but when schedule

This has been observed repeatedly, Fred Brooks wrote a whole book about it. Everyone says they've read and agree with "The Mythical Man Month" but when schedules loom the first reaction is always to throw more people at it. An expensive hot-shot added late in the project can grind the gears much worse than a green trainee.