So, what you're saying is...STR and DEX are power and control, while SPI is both power and control.

Now, one must wonder: what happens if you give a muscle dude and a mage equal amounts of Essence and pit them against each other? Does it not appear to make sense that the mage, who can devote all their Essence to one stat would be greater than the muscle dude, who has to split their Essence between two stats?