The difference is, FGT that Starmer has a great deal of nous, and Trump has very little. You don't get a law degree (at least in the UK) without training in assessing facts in detail before reaching a conclusion, and in where to look to find those facts. You don't build up a successful and respected law practice, or rise in a few years from newby MP through head of a political party to Prime Minister of the UK, without learning a lot about managing people and making decisions which affect others as well as your bank balance.
Trump, on the other hand, has learnt almost nothing since he was a small boy. According to his teachers he didn't learn much then either. He has several bankruptcies under his belt, he believes whoever is brown-nosing most assiduously, he makes his decisions according to who is most resentful of on any given day and changes his mind more often than his socks then denies that he ever said things that are publicly available in black and white. He is the leader and protector of millions of Americans, but he is removing every federal organisation which does anything for their welfare when they are in difficulties - and his advice to them is that if they don't like it they can go live elsewhere, as though beng a US citizen is a job you chose, which you can just quit and het another tomorrow.
And that is not even mentioning his frequent presence on Epstein's passenger list and photos circulating of a charge sheet naming him and Epstein on a particularly sordid charge.