"as if he had been" or "as if he were"

Question

G. H. Hardy, "A Mathematician's Apology":

Even in mathematics, history sometimes plays strange tricks; Rolle figures in the text-books of elementary calculus as if he had been a mathematician like Newton;

Can I substitute the past perfect for plain past simple and say as if he were?

Answer 1

In the phrase as if he were, were is not a ‘past simple’, although it looks like it, and in as if had been, had been is not a perfect, although it looks like one.

These are both irrealis or ‘unreal’ uses of the past forms of be and have. Were here is irrealis present tense, and its past form is had been.

This is explained in more detail here, section 2.3.

Consequently, you cannot substitute were in referring to Michel Rolle, because that is present tense and Rolle has been dead for almost 200 years.