How many do you think is realistic? Reducing your revenue by an order of magnitude to reduce your headcount by an order of magnitude seems like a bad plan.
Right now there are 360,000 blue check marks on Twitter. If I spot you the first million blue checkmarks and the first 100,000 business profiles, that's only $144M of revenue per year. Even if that is 90% profit, $130M / year profit on a $50B investment is not particularly brag-worthy.
Once a company gets big enough, 95% of an employees job is navigating the bureaucracy. So the head count goes way up.
Companies tend to hire more employees as long as the marginal benefit to doing so is greater than the marginal cost. Even minor improvements to a product like Twitter can boost revenue by millions. Reducing the headcount might not maximise their income.
There will be exceptions though. Valve does lot more than most video-game companies with far fewer employees.
Wait a minute when did Valve go back to being a video game company?
• How many are engineers?
• How many work in customer service?
• How many are in compliance?
• How many are in marketing?
• How many are ICs and how many are managers?
• How many are in HR?
• How many are in finance?
If he charged $2 / month for an individual to get a blue check and $100 / month for a company to get verified then eliminated ads, could he get the staff count down to under 100 people?
I remember when Facebook bought Instagram. Instagram had something like 13 employees. Why does Twitter need two orders of magnitude more?