More or less sections/subsections in a journal article?
As you point out, this is likely field specific and also depends on the type of article you are writing within that field. The old saying of "Everything should be made as simple as possible, but not simpler" applies here too. If your article doesn't need a lot of subsections and subsubsections, then don't use them. However, if they are needed, well, then they are needed!

I have found that the STROBE statement and the CONSORT statement are very useful for helping structuring articles that are of the statistical type. Perhaps similar documents are present in other fields too?

But, as JeffE pointed out in a comment to your question, pick the structure of the article that makes it easiest on your reader to understand your results and how you arrived at them.