After having made the M1 Garand needlessly large and overweight - by insisting it be produced as a 30'06 rather than the 276 Pedersen for which it was developed - the US War Department experimented with a shorter version, the T26. Too little, too late. It came to naught.
I'm not sure the Spanish FR8 is properly considered a proto scout. The FR8 and the FR7 - same idea but built on the 1916 small ring action - served as trainers for the Spanish military until they had enough CETME selfloading rifles (HK91 precursors) to go around. They were not built to be lightweight fighting carbines like some of the other proto scouts, but they were shorter and lighter than the full length predecessor from which they were assembled. Those I've seen were rougher than a cob and the rear sight looked like a "C Minus" middle school shop project. They were made into the 1950s.
But for these examples, it seems that most armies of the world forget the value of handiness in the century between the American Civil War and the Second World War, but Colonel Cooper noticed, and added their merits to his scout rifle concept.