Elon Musk said in an email on Monday that he must approve all new Tesla hires.
• That's no small task: Tesla increased its head count by about 30,000 in each of the last three years.
• Musk's oversight could amount to hundreds of hours of extra work and slow Tesla's hiring process.
Elon Musk told staff he wants to approve each person that is hired at Tesla, but that won't be…