There are two ways to do tariffs.
First, the classic way. Gather a group of "experts". These are academics, economists etc. Then gather tons of data. Do a detailed analysis. Gather a group of better "experts" to review the options. Select a small number. Get the final decision makers together to determine the "best" That takes years.
Second, is to tariff everything at a massive number in a short period, say week. See who screams the most. Then tariff those left shouting the least That takes about a week or two.
Guess what just happened?
And we did not need a single "expert". It also was cheap.
An example is the atomic bomb project. Yes there was a bit of study but the explosion was necessary.