I imagine that there are lots of capable folks in the Midwest, Texas, etc. that run banks, work in state government, etc. that might bring a healthy perspective to the swamp. But - Trump doesn’t know them. So he draws from the people he does know.
Of course if he found them in his own companies (which I am sure they are as capable as these GS guys) he would be called out on cronyism.
You might be on to something.
As much as Trump resinates with regular folks all over America, he definitely is (he says so himself) part of the bubble of NY top executives and high finance. He strikes me as an unusually patriotic man among his surroundings... but this is his world and I think his familiarity with this bubble is both his strength and achilles heel...