Please produce your evidence that Mussolini's ascent or style of government was a "society ruled or controlled by people of great wealth", as defined by Wikipedia.
Fascist political philosophy is about racial purity, militarism, autarky, and suppression of dissent through political violence. In fact, one of their methods of enacting such worldview was by appropriating the wealth of rich people to advance their own purposes.
If you read your link, you will discover it's not focused at Mussolini's fascism at all, but still talks about the merge of the government and corporations... Because it's a very important feature of that regime.
Fascist political philosophy is about racial purity, militarism, autarky, and suppression of dissent through political violence. In fact, one of their methods of enacting such worldview was by appropriating the wealth of rich people to advance their own purposes.
Please educate yourself, it's free: https://en.wikipedia.org/wiki/Fascism