Sure, he's saying that one [or two] can travel faster than a squad.
But why quote Kipling?
It's in character for a military officer of the time. Classical education.
This type of quote, off the cuff being able to fit a literary quote to a given situation is a kind of 'verbal armoury' of sorts. This type of education and upbringing would arm such a person with a lot of similar quotes, one for each situation. Some people in this day and age can do the same with pre-learned jokes, to be fired off without needing to come up with an original witticism.
I recall a similar one - though I cannot recall the source - from a naval story. In the British navy a seaman must ask a senior officer's permission to grow a beard. He then has two weeks trial period before showing the result to the officer to obtain the necessary permission to continue.
The officer writes just "Matthew 26:41" on a slip of paper & hands it back to the seaman.
On checking his bible* he discovers the passage - "The spirit is willing, but the flesh is weak."
*One must assume everyone in those days would have a bible and be aware that's what the reference indicated.