i don't exactly know what PwC is but with a little search it seems like they have a foot in financial services. so it is possible that "blockchain expert" in their definition translates into a person who has been making speculation in the cryptocurrency market. and we all know how stupid that kind of people are and they are far from experts but we have a lot of them.
it certainly wouldn't be the first time a company does this though.
They're a big accounting firm based in the UK. They tend to be more involved with consulting/advising/auditing the financial matters of a business rather than market speculation. Their clients are usually large businesses and corporations.
then it doesn't make sense to me because that is the only way i could explain this kind of big number. otherwise we don't even have enough blockchain experts to have 400 of them only working with this firm alone!