I don't think trying to beat Trump with another rich actor is such a good idea. We need to combat him with experience, if this government fails as it may.
Oh really, last I recall, Obama was pretty much inexperienced when he beat McCain...or how about Bill vs Bush Sr...pretty obvious who was more experienced...oh and Jimmy vs Ford.
Last time an "experienced" or "old" Democrat actually won, well that Democrat literally had the legacy of another inexperienced hearthrob to ride on.
Oh, but there are others. Truman was plenty experienced over Dewey...barely won that and most people counted him out...narrowest win besides Jimmy.
FDR wasn't as experienced as Hoover...or maybe he was depending on how you look at it, but he was certainly not what you'd expect...oops.
Then there's Wilson, easily the least experienced compared to Teddy or Taft or even Hughes...oops.
Cleveland was a two year governor before defeating Blaine and that and a termer against a Congresscritter AND President in Harrison.
So basically, besides Truman and LBJ, every post-Civil War Democrat that won was arguably less experienced than the Republican.
Think about that a moment....
In comparison to George Clooney, all of the examples you mention are basically John Quincy Adams in experience terms.
Clooney was considered as a contender for Senate in California and bookmakers doubled his chances after marrying his wife, who is a prominent human rights lawyer and activist. He clearly doesn't need experience after this election.