This is one of my favorite quotes:
"The finest workers in stone are not copper or steel tools, but the gentle touches of air and water working at their leisure with a liberal allowance of time." -Henry David Thoreau
The only thing I don't like is the preposition in! ;)
Paraphrasing the idiom results in ...
The gentle touches are the tools and finest workers in stone.
Is that word fine there? Can we have anything else that looks more natural? Maybe "...of stone..." or "...on stone..."
If the perplexity is due to its idiomatic or poetic use, let's change it.
The Chinese are the finest workers in parasols.
Don't you think "...on/for parasols. looks better?
Had it been some art/act (or for that sake any verb) itself, I wouldn't have any problem:
The Chinese are the best in paragliding.