tl;dr: Hire a hardworking, versatile person instead.
Couldn’t agree more. I’ve been in marketing for the best part of 8 years, and still don’t have a specialism. It’s really beneficial for small/new teams as I can identify areas needing attention and draw on a really broad range of skills and knowledge.
I’d advocate start-ups hiring experienced all-rounders, then farm out to specialists or recruit if it becomes financially viable.