That is largely down to the choice of multiple words to express similar concepts in English (due to its mongrel roots), and those having subtly different meanin

That is largely down to the choice of multiple words to express similar concepts in English (due to its mongrel roots), and those having subtly different meanings, hence the high information density in English. So in one having access to an expansive enough vocabulary, one will often use fewer of the core words. Partially as a way to remove ambiguity in written English (which can be very difficult), partially to write a shorter sentence than would be the case using Germanic root words alone. For the second phrase you quoted, I could have written 'the heart of the tongue', but that could be read to imply a different meaning.