Experience I made with the Linux/MIPS project: a small number of people
is actually strong enough to contribute to the project. Those don't
handholding and if they ask question it is because is because of very
unobvious things or because of external things that can not be found
in the code. Almost the entire rest of developers doesn't have what it
would take them to bite through the mass of minor and major showstoppers
even with handholding.
Ralf