Thanks, read the paper about testing the mythical man month theory.
Seems the conclusions are: fewer people is better; only one "organisation" or group should contribute to the code; ownership should be at the lowest level possible, not a high up manager; and knowledge retention is important, effectively manage people leaving and make sure the design rational is well documented
Till today I still share with my coworkers this 15yo article from Microsoft Research:
https://www.microsoft.com/en-us/research/blog/exploding-soft...