This has been obvious for ages. The terms "left" and "right" are largely irrelevant in today's politics.
Putin is not left-wing. Communism in Russia died decades ago. Putin is authoritarian and expansionist. This is more like pre WW1 power politics than anything since.
Banks has been boasting about how much he put into Brexit since before the referendum and has been saying that he was going to set up a new movement.
It was his ideas about marketing the Brexit message which won the day.
He knew that the propaganda about élites and immigration (aka cultural supremacy) would resonate with the public. Think back to all the hatred of "Tory toffs", "out of touch Oxbridge élites", "unelected Brussels bureaucrats", etc. Of course, he has a point, but the truth is that he belongs to an alternative élite which wants to take over from the establishment. He needed the working class, angry and disillusioned foot soldiers to deliver the votes, so that he could claim it's all about "democracy" and the "will of the people".
The big difference between these élites is in their social values. Again, this is more like pre WW1 politics with Conservatives and Liberals, before universal adult suffrage and the rise of the Labour Party.
If that seems familiar, it's because it's succeeded before and, if people don't watch their backs, it will succeed again.