Probably quite high.

Google's culture and hiring process is so well documented at this point, I suspect any suitably talented individual could appropriate some cultural fit.

Of the (current and former) googlers I know personally, they are a mixed bag but there are some traits that are more common. Self assurance and the uncanny ability to never be seen to be demonstrably incorrect are prevalent tbh - but that applies equally to most of the industry.

> the uncanny ability to never be seen to be demonstrably incorrect

I think that may be very easy to do, just state that everything you say is just a theory or your opinion... but this is just a theory.

I'm an interview at a FAANG company, and I did and will reject people if I have the feeling that they are not a cultural fit. (e.g. being a dick, arrogant, ...)