I agree with you on "don't do big software project" Specially do not fast scale them out to hundreds of people. You have to scale them more organically ensuring that every person added is a net gain. They think that adding more people will reduce the time.

I am surprised on the lack of creativity when doing these projects. Why don't they start 5 small projects building the same thing and let them work for a year. At the end of the year you cancel one of the projects, increasing the funding in the other four. You can do that every year based on the results. It may look like a waste but it will significantly increase your chances of succeeding.