It certainly is true. There is a famous saying "Even the clever crow eventually eats his own shit." No matter how sophisticated the financial markets are, everything ultimately depends on the amount of capital you have. If you have a lot of money, almost any strategy can look perfect, but with limited capital, all you find is struggle.
Leopold made his biggest mistake when he increased his leverage. If you already have plenty of capital, then what is the need for leverage? I have gone through all of these mistakes myself. Even today, I actively trade, and I currently have both gold and silver hedge positions open but I use only 1× leverage.
To me, leverage is simply another name for destruction and ruin.