This article is partly about the longevity of startup dev teams.
Here is a simple true fact:
If your hiring pipeline isn't diverse (in a bunch of different ways, but in particular in the ways that represent "the opposite of the approach you just spelled out for building up a team"), then it may be fast and effective, but it is also brittle.
Every team loses people, no matter how carefully designed they are. Companies with huge traction and close-knit management teams where everyone likes each other lose cofounders. People leave, for all sorts of reasons.
On brittle teams, when one person leaves, a whole bunch of people follow.
You want to build a team that is resilient to one or two people leaving every once in awhile. Diversity --- not in the "Benetton ad" sense, but in a more fundamental sense --- is an extremely good mitigating strategy.
You may not care about team resiliency and longevity; "throw it out the window" to get to release and all of that. I think that's a bad plan (getting to a reasonable successful first release only to have your team implode is not a really good use of your very limited window of time to build companies in, is what I think), but that's neither here nor there.