To hire so many you have to hire a lot in parallel. Also, even once hired, probably the engineer shouldn't have "interview more engineers" as his first priority.

I don't think many people on this board comprehend that there exist professionals at most companies whose sole responsibility is to identify, recruit, and onboard new employees.

Or that most companies are willing to hire people who aren't perfect candidates because a fair amount of internal training is expected. Hiring only unicorn candidates who already have the perfect qualifications and don't need any training/onboarding is a peculiarly Silicon Valley phenomenon.