Efficiency is something of a red herring when it comes to a power source that requires no fuel. Sure, you'd get more power from the same wind turbine if it had higher efficiencies, but it doesn't change the operational cost.
The discussion of work hours strikes me as a problem with the company he worked for. If your employees are normally working 100 hour weeks, then you need 2.5 times more employees. And if they have surge work that can go up to 140 hours per week, then having more employees makes even more sense.
Sounds like some former coal workers need training for new jobs.