Quite an interesting speculation about compound mastery. Looks like it's efficiency is limited, but "when it works", you don't regret the TM points.
I tried to sum up your theory with a graph (values are NOT accurate and i'm bad at drawing curves). Still I wonder if it's correct:
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Tunie, 3124 Cat: "She's over bored, and self assured" <- Oh no, I know, a dirty word...
Tostaky, 1144 Fox: "Soyons desinvoltes, n'ayons l'air de rien" <- Aaah!! Tos-ta-ky!!
Tartiflette, xxxx Sheep: "Right Next Door To Hell" <- Why don't you write a letter to me?