Notably Douglas Haig fits almost perfectly into the Stereotype of the Cavalry Officer. His family had money, they were Haig & Haig Whisky, and technically Gentry.The regular Cavalry were the lest regarded, by the rest of the British Army, of the four fighting branches of the Army, Corps of Infantry, Royal Engineers, Royal Artillery and Corps of Cavalry. Winston got such a low mark in his final examination at Sandhurst, that his father could only secure him a commission in a second class cavalry regiment, the 5th Hussars. If you had brains and little of no money, you went to Woolwich, and joined the RE or RA, if you had money but no great social class, you went into the Infantry, the Rifle Regiment if you had a brain. If you had the right social class, money and a bit of a brain it’s the Household Division for you, and if you were thick but had a bit of social class, you were for the Cavalry. Prior to the Second World War, I doubt that there was a single officer in the regular cavalry who possessed a university degree, there would have been a number in the Yeomanry who possessed a professional degree , lawyer, accountant even on or two mechanical engineers. Note while the infantry especially the Rifles would have had a few, as would the Artillery, if you are looking for men with degrees it’s the Engineers or newly formed Signals, you need to look at. As for the Household Division, they were a law unto themselves, it tended to be who your great great grandfather was, or who your great grandmother slept with, that counted.
However, young Douglas failed to graduate from Oxford, and actually flunked the Staff College Entrance Exam, he got in by social connection.