Yes, they are badly implemented, I agree. He is calling them reciprocal tariffs though, which implies he will lower them as they lower theirs. I don't think he's chosen a good way of estimating theirs, and so I don't think it's a particularly good policy, but reciprocal tariffs in principle are a good idea.

Even though his first pass crude approximation is stupid, it's really how other countries react, and how he reacts to them that will determine whether they behave like reciprocal tariffs or not.

There is a baked-in plan to test if they're going to work: they are formulaic, based on the trade deficit. Supposing that deficit falls, they will automaticlaly readjust downwards. I don't think the trade deficit (particularly restricted to goods, as they did it) is a good proxy for that, but it's also not completely untethered from reality.