How will you be able to discern a charlatan from a good fit to your company, if what they're supposed to be at at is totally alien to you?!
Go to the library, ask around, google. Even if you completely fail at marketing, you've learned something about the skills you're missing. Which your company is missing.
Even if startup founders had time to spare spending a month learning how to doing each and every task they needed to hire for (and trading money they have for time they don't is the whole point of hiring) they'd (i) have no time left to focus on the core business (ii) do a really bad job and (iii) having barely understood the basics, run exactly the same risk of hiring good interviewees with the right credentials that were actually bad at their jobs. Maybe they'd even be more sympathetic to the bad hire because well, he's better than I was
That’s not to say I disagree with your points in general, but just that hiring is every bit as much of a minefield as doing things yourself. In either case you have to understand what is most crucial for the next stage of growth and prune everything else obsessively.
When I started my business (non-tech), i knew very little about sales processes or relationship building from a sales perspective. One of my first consistent customers (disclosure: he is also a close friend) is a sales professional. I learned the very basics of sales, and came to him, asking what were probably dumb or basic questions, but he was more than happy to answer them and also point out where, as the company grew (and hopefully grows!), what to look for in sales people and relationship managers. While I still know little in comparison to him, I know some of the right questions to ask, what to expect from those questions, and what sorts of answers I should be looking for. He also knows that I can call him with deeper questions and to help me evaluate a sales-related situation as it arises, and he'll give me a no bullshit honest answer.
Find people like that.
