Brook’s law
‘Brooks’s law is an observation about software project management according to which “adding manpower to a late software project makes it later”. It was coined by Fred Brooks in his 1975 book The Mythical Man-Month. According to Brooks, under certain conditions, an incremental person when added to a project makes it take more, not less time.’
https://en.m.wikipedia.org/wiki/Brooks’s_law
https://www.leadingagile.com/2018/02/lines-of-communication-team-size-applying-brooks-law/