I have yet to encounter positive solutions to those questions, as usually increasing headcount does not relieve pressure on team members - it's used to enable quicker replacement by yet-another-junior-to-burned-at-the-altar who will leave after gaining experience and burning out.

The classic "we have niche languages" solution to that is to enable on-the-job learning of those, and not just doing simple fact checking on whether someone honestly claimed to have learnt Popular Language X as claimed on their CV.