I believe your answer is based on the assumption that founders work closely on every details, and working on several startups might get them distracted.

But how about recruiting the right people for the right job (well, this wouldn't be possible for startups with meager fund though) in each of the startups so that the ideas get implemented as they should, and the founders, rather than actually developing the projects ground up, merely act as project managers, monitoring the progress and validating the results against their vision.

That's certainly possible, but even at that higher level of abstraction, there's still a ton of work to do. I can't imagine a PM at Facebook in 2007 or Google in 2003 having the time to run multiple projects at multiple companies.

It might work for smaller companies, but eventually you'll either have to focus on one, or zoom further out (and essentially become a VC).

This is exactly what I'm talking about. Steve jobs example cited above.

That only works if you have a lot of money already (and I mean basically a seed round of investment). Otherwise, you'll need a technical co-founder at the very least.

The way they manage startups, yes. It's however very difficult to ideate so many (which these guys don't), but giving shape to a couple of ideas and managing them independently like these guys do is not impossible it seems.

Take Steve Jobs for example. He worked with Apple, NEXT and Pixar parallelly for sometime I believe. Other than that Apple itself is no lesser than multiple startups/companies as it is - a computer company, software company, mobile phone maker, digital distribution company, and more.

If I remember correctly, he was at NEXT, which then got bought by Apple. He later got involved with Pixar, but not on an in-the-trenches manner.

It could definitely work, but you'd need established teams that can basically function on their own. At this point, you're a general, not a soldier.

Right, at this point, you're not a soldier. You're a commander leading a battalion of hand-picked soldiers who are probably smarter than you (if you have funds and can hire well). This way, you're multiplying your effort by not doing the ground work yourself.

With two hands and 24 hours in a day, it's just too limited how much you can accomplish yourself.

The key thing to remember is that Steve Jobs was more of an "investor" and an "advisor" at Pixar. He played no day-to-day role at Pixar. He certainly did not involve himself in any specific product development or management.

He was working at NEXT and Pixar in parallel.