I just meant that with the best care and a great driver he might have gone faster. look in 1978 nobody expected Clint Galbreath to be the guy who would shatter the elusive magical mark of 1;50. right? Only proves what a natural the horse was. That's all. Clint's bath certainly wasn't the best in racing in those days.
As a certain french canadian driver we all know and love once observed, referring to Niatross - "Clint didn't make that horse, that horse made Clint'
as for your other point - that was a great year and crop. many of the Big 5 took turns beating and upsetting each other