The existence of the Autonomous Car Unit was also a management problem.
The unstated truth in the "mythical man month" is that you can't rescue a project by throwing people at it if the project is out of control because of poor management.
Stellar management can do almost anything.
Mediocre management bumbles around creating failures.
But I guess the keyboard design is a managment problem not a engineer problem.
"The mythical man month" should not be interpreted dogmatically.