There were a lot of great lines in The Counting House, but have found myself coming back to this recently:

While there is a requisite amount of grinding (and requisite amount of labor), just throwing more resources at a problem is not itself sufficient to generate performance. Some strategies are more labor intensive than others. But they all run into diminishing returns, hard.

I don't think it's quite as bad as The Mythical Man Month ( en.wikipedia.org/wiki/The_Mythi… ), directionally... there are similarities.