Some permutation of "pair programming" helps with "mission critical" software execution risks. We call this "the bus test" in DC no-nonsense engineering. Project execution must survive anyone getting "hit by a bus."

It does not have to be pair-teams. It can be 3-teams that review each other's code. Crafting shared libraries also helps focus multiple developers around code, docs, calling semantics and help surface implicit performance expectations or penalties early.

I have been the hero developer cranking 10K lines of C per month. But divide and conquer where software development MATTERS isn't very wise. Methods make sense when dozens of jobs, thousands of lives or millions of dollars are at stake every week and month of a project.

We used to call virtuous redundancy "belt and suspenders."