Earlier quoted context omitted.
As a fellow experienced marketer I would implore you to not use the term "marketing guru." The word "guru" has a really bad connotation with all of the info product snake oil salesmen and wannabe marketers out there. The reality is that marketing is an increasingly specialized and technical domain requiring knowledge of coding, data, etc. and it can be hard enough as it is to help people trust we're not all scammers…
The problem with finding great marketing people is that there's no barrier to entry into the profession. Anyone can (and does) say that they're a 'marketing expert,' a 'growth hacker' or a 'marketing guru' [gag]. To be great at it, yes, people need to have technical ability. But they also need a sort of sixth-sense intuition (visual sensibility, language skills, an understanding of psychology) that can't be taught or…
And yes, I agree it takes a great marketer to spot others. It would be a like a designer interviewing someone for a coding position. They might say lots of technical jargon type stuff and you'll have no idea what is made up, what is buzzwords, and what are signals that say a person is good at what they do.
I wonder if companies would pay for a marketing consultant to help them hire.