Page 70; Pronouns section say that
it, they and other personal pronouns are used to mean the same actual thing as the antecedant.
ex:
The money spent by her parents is more than it was expected to be.
that, those are used to create a copy of the antecedant.
ex:
The money spent by her parents is less than that spent by her children.
Her goods are low quality than those of her competitors.
Agreed and clear!
Moving to page 97, modifiers section
The acquaintances whom we like most are those who flatter us best.
Here we are trying to talk about the same group of acquaintances (antecedant). So why are we using those instead of they? Using those is creating a new set of acquaintances who are not the same (can be other acquaintances who are our neighbors, not necessarily the ones whom we like)!
I agree that by using those, the sentence is more pleasing to the ear than using they. But remember the very first rule of GMAT preparation is not to believe in your ear. So can someone clear me about this topic? Thank You