One of the most confusing parts of the English Grammar Profile is when explanations don’t match the examples given. This is a real problem when it is meant to be extremely specific and various very similar forms are rated at varying levels. In this example below, you can see that “of” is required for this point to be C1, yet the example does not contain it:
52 NOUNS phrases
C1 WITH POSSESSIVE ‘S WITHOUT NOUN
Can form complex noun phrases with noun phrase + ‘of’ + noun phrase + possessive determiner ‘s, omitting the noun where it is previously mentioned.
Our after-sales team now is perceived as faster, more qualified, friendlier and more efficient than our competitors’.