Whereas, if I am interpreting them correctly, what they are saying is

(1) People say that high IQ is the reason Newton invented calculus.

(2) High processing speed and copious amounts of RAM don't themselves suffice to invent calculus.

(3) Therefore, "High processing speed and copious amounts of RAM" is not a good description of high IQ.

Personally, I'd say that 'high IQ' is probably most useful when just used to refer to whatever it is that enables people to do stuff like invent calculus, and that 'working memory' already suffices for RAM, and that there probably should be a term for 'high processing speed' but I do not know what it is/should be.

EDIT: that is, I think that Newton scored well along some metric which did immensely increase his chances of inventing calculus, which does extend beyond RAM and processing speed, which I would nonetheless refer to as 'high IQ'

tabooing IQ would almost certainly be helpful here.