“IT is mainly introverts doing mysterious stuff no one understands”
It is a very cooperative field where everyone has different roles with different responsibilities, but everyone has a vague idea what everyone else is doing. Most of the time is spent making sure everyone else can also use the systems you build, not just yourself.
It wasn’t actually more efficient. Having all of you’re guys in a huge box makes it easier to hit than having you’re infantry spread out. It was mostly a morale thing, having other soldiers within arms range made you reconsider running away. While being engaged with huge volleys by these squares made you very much consider if you should run anyway.