facilities may have greatly improved but has the constitution and soundness of the thoroughbred depreciated?

​The much-maligned, including by me, Matt Chapman, in informing his viewers that Cheltenham Gold Cup winning trainer Arthur Barrow was still hale and hearty at 80 and that his Gold Cup winner Master Smudge ran over 100-times, set me thinking. Galopin Des Champs, for instance, will, if we are lucky, have a career-span of forty races, though less, I suspect. Constitution Hill might not go beyond twenty at his present trajectory.
Master Smudge was no freak, by the way. Yesterday, I wrote that Spanish Steps ran 78-times in his ten-year career, that is an average of 7-races per season. A quick browse of a few of the books that are close at hand resulted in the following list. Monksfield, twice a champion hurdle winner, ran over 70-times. Sea Pigeon, also a dual champion hurdler and possible the greatest dual-purpose horse of all-time, ran 45-times on the flat, plus 40-times over hurdles. Moscow Flyer, dual Champion Chase winner and one of  the best 2-mile chasers of all-time, ran 41-times. Desert Orchid had a 55-race career. Silver Buck, Cheltenham Gold Cup winner, ran 45-times.
Of course, the facilities at any trainers’ disposal can be many times better than the facilities trainers used back in the 1950’s, 60’s, 70’s and possibly into the 1980’s but does that mean a horse in training today must therefore run fewer times than the days of the golden era of hurdlers, for instance? I do not recall a trainer when interviewed about one of his, and back in the sixties and seventies it was usually a male trainer, claiming that his horse ‘enjoyed being fresh’ and the phrase ‘super-fresh’ was totally unheard-of until Dan Skelton used it as an excuse not to run a horse and to demonstrate his skill at getting a horse 100% fit at home without recourse to running them in a race. To give Dan his due, he has admitted keeping Protektorat ‘super fresh’ proved a mistake.
I always raise an eyebrow when a trainer, even though they either have a point or are making a point, asks the question ‘where can I run him’, there are no races for him? Back in the day, it was customary to run horses destined for the Cheltenham Gold Cup under top weight in a handicap. A week before Silver Buck won the Gold Cup in 1892, he had won a handicap chase at Market Rasen with 12st 7Ibs on his back.
Sir Gino, for instance, is now liable to go to the Arkle Chase at Cheltenham with one novice chase as experience and a career-span of only half-a-dozen races all-told. His oft-maligned, though brilliant trainer, seems likely to decline a 2-mile novice chase at Bangor for Sir Gino as it is too close to Cheltenham, even though there is over 2-weeks between the races and it would be unlikely that Sir Gino need get out of second gear to beat the type of horse that would take him on. A far easier mission, I would guess, than what Michael Dickenson asked of Silver Buck all those years ago in the Cox Moore Sweaters handicap chase.
Trainers no longer choose to ‘boldly go’ where his or her contemporaries ‘fear to tread’. There was a time when a trainer would not hesitate to run a horse twice at the Cheltenham Festival if plan a had gone astray. Nowadays they would be shy away from doing so in case the ignorant few went to the press claiming some form cruelty was being enacted. 
If the major stumbling block to a trainer running a good or top-class horse more often is the programme of races, then the National Trainers’ Federation should instigate talks with the B.H.A. and the racecourses to provide the sort of races that are missing from the calendar, especially in the first month of the season proper and in the lead-up to Cheltenham.
Would any of the greats of the sport I mentioned earlier have achieved more if they were run as sparingly as today’s top horses? Or should that question be phrased the other way around?