@ian_macfYou're confounding two different hyphen usages. A compound, multi-word adjective is typically always hyphenated. It's the paragraph hyphenations which are the bigger issue.
However, it's also entirely possible that Sir Churchill simply preferred avoiding multi-word adjectives entirely, and thus simply stuck to single word adjectives. But it'd take a fairly deep-dive into his writings (i.e. his personal letters) to determine this, as like many, his Autobiography was likely 'polished' by someone else.
Some famous figures were notoriously literate—writing often and fluently—while others stuck to the basic facts without embellishing much. So to justify the publishing contract, publishers aren't shy about professional 'embellishments' by trained editors/ghostwriters or collaborators—like wives, mistresses or lovers (both sexes).
I'm not implying anything about Winston himself, yet these things do happen. How often is never very clear (i.e. anonymous), yet ghostwriting is a highly lucrative profession for a reason. While Sir Win was a very eloquent speaker and an active letter-writer too.
Again, no two writers ever write the same way as any other. They may follow similar styles, yet everyone is uniquely themselves, except for those who are paid to sound like someone else. ;)