For banking elites, the most advantageous situation would be to have a single worldwide fiat currency, under their control. We have had something like this for the past few decades, with the dollar being the global reserve currency. However, this situation cannot last indefinitely, and there are other emerging economies that will soon rival the US in size.
The next best option for the elites would perhaps be the gold standard, because it does provide some influence for those who control gold mines and large reserves of gold.
The most disadvantageous situation would be having large economies on fiat currencies that are outside their control.
Many well meaning folks, deeply angry about the banking system, have unfortunately bought into false theories about the root of their troubles. They believe that the gold standard will save them, despite the fact that gold standard actually facilitated the Great Depression of 1929-33. They angrily allege that the fractional reserve system allows banks to "print money", although it does nothing of the kind.
It would not surprise the astute observer that peddlers of such false theories, sending simple-minded folks on wild goose chases, are themselves linked to banking elites.
For example, the Ludwig von Mises Institute for "Austrian Economics", with which US presidential candidate Ron Paul is associated.
Ludwig von Mises was closely associated with one of the ideological fathers of the European Union,
Richard Coudenhove-Kalergi. He worked under Coudenhove-Kalergi's leadership on currency issues for the then proposed Union.
Coudenhove-Kalergi was on very cordial terms with banking elites. Indeed, he states in his book
Pan-Europa that -
“Early in 1924 Baron Louis Rothschild telephoned to say that a friend of his, Max Warburg, had read my book and wanted to meet me. To my great astonishment Warburg immediately offered a donation of 60,000 gold marks to see the movement through its first three years. Max Warburg was a staunch supporter of Pan-Europe all his life and we remained close friends until his death in 1946. His readiness to support it (the movement) at the outset contributed decisively to its subsequent success."