I think you might be more successful in your search if you start looking at it from the bottom instead of from the top. Hypertrophy is the result - but what produces this result? A major factor is increased synthesis of contractile proteins. Almost always opposing processes in our body happen simultaniously. So we have breakdown of contractile proteins vs. synthesis of contractile proteins. If the first pathway is more strongly activated we achieve atrophy, if the second one dominates the result will be hypertrophy.
So it might be intresting to look what causes an increas in contractile protein synthesis and a decrease in contractile protein breakdown (e.g. hormons, look factors, etc.) And then go up a notch and look what causes this , etc.
But personally I do not believe that this search will lead anywhere. In such cases I always think back to the first semester and what a physics professor said in his first lecture: "We understand the real small process, llke intramolecular interactions and the huge ones like gravity and the lever rule but we are not nearly smart enough to extrapolate the big ones from the small ones."
So basically it would help you more to study training results or to study physiology and not "waste" time trying to draw training conclusions from physiology.