As I have pointed out before, "deep pockets" is actually a disadvantage
With a million or less, he could assess the small companies that aren't covered by analysts and so on, to find one that was (1) great (2) cheap
The lack of money is not the deficit that stops you (and me). Mostly, it's effort, and self-confidence in your own considered opinion when it is contrary to everybody else. To buy when others sell - because you've done the research, and trust your judgment. It's mostly an emotional or moral quality. If your judgment is wrong, you have a lovely learning experience that cannot be obtained in any other way (and Warren Buffett has had that experience).
Of course if he announced which stocks he picked at the time he purchases them the price would probably increase. Heisenberg and all that...
I often wonder if people like Jim Cramer end up manipulating the market just by talking publicly. And is it illegal? If Cramer says "I just bought such and such stock and think it's a great buy", and the price goes up because of it, and he sells his shares for a profit, is that illegal? He simply stated a fact and his opinion. Where is the line drawn?
The Berkshire Hathaway stockholders might object. It's a dumb objection, but it's probably enough to get past summary judgement.
But enough to buy a controlling stake in mid sized companies, that not.
Happy middle's where you want to be.