What he's said is kind of like saying "a war isn't the generals, it's the soldiers!" I mean, yeah, for certain things it absolutely comes down to the individuals and he's correct. But to diminish or toss out altogether the importance of higher level strategic thinking vs tactical is rubbish.
And I'd agree the philosophy/environment of the club matters too, but that could be fluid as well, with owners changing etc.
Really it's just impossible to pin down how much each contribution matters and it wouldn't be a hard rule anyway.