Lagat came to Li as a 22-year-old 3:37 guy, I think. He never in any single year or two made the kind of percentage improvement that Andrew Wheating made.
Farah came to Salazar as already a Oly/WC finalist. He had trained in Kenya....and THEN made "amazing" improvement.
I still remember a UK press interview where Farah said he was confident that Salazar could get him the "extra 2%" needed to win a major championship. Two percent is the improvement Kelli White got from Victor Conte.