If it is ethical to clone people at all, then it would be ethical to clone those people. What is it about these particular people or types of people that would make it unethical?

Likely some countries would want to clone their best athletes. If it would be allowed. With intelligence it isn't so straight forward as different people can have different interests. Perhaps physical abilities are more about the genes here.

Above all, let's remember that clones that we can make now aren't so good as identical twins in nature. And identical twins can be different.

If it is unethical to exploit persons, treat them as a means rather than an end in themselves, define them in advance of their existence as useful for some purpose, then YES: it would be unethical to clone Einstein.

It would be unethical to clone anyone for some particular purpose.

Of the 7.5 billion people on earth, it is likely that at least several, maybe hundreds of people, or thousands are as smart as Einstein. Besides, it isn't just "smarts". It's also creativity, determination, patience, conducive environment, etc. Do we know how to raise several baby Einsteins so that they would perform as ordered? No.

We could use a few Jesus's too. A lot less Judas's.

it does not matter, as you can not possibly do that. You would have to clone their entire life and world of influences, from what they read, to what they ate! A person with same DNA is not the same person. Not even the same body.

Anyway, I thought you meant Einstein, the grey parrot; but there´s no need, just take another healthy parrot and instruct him from birth to talk and discuss current affairs