Lin Yu-tang was a great scholar and was labelled a "Master of Humour"
in the 50s and 60s of last century. We know that during that era, that Chinese went to study in the west were not many. Scholars of such, who had studied abroad occupied excellent positions either in the government or in the academic institudes.
Now, Chinese come to the west for study is not a particular matter. For example, I think even in this Historical Forum or the others, there are many PhDs., Masters, and bachelors.
Lin Yu-tang's English is good, but it is still not so good as to claim Excellent! Probably there are so many who know and master in good English nowaday.
I don't think Lin's literary level is better than Xia Yen Zhun, Zhu Zi-qing, or Liang Qi-qau. What Lin is different from the others is that he has a high academic degree.
In "The Century's English and Chinese Dictionary" edited by lin himself I found English mistakes in the prelude page.
"Tools" for English learning today are much easier than ever, those who want to master this English language is not inaccessible any more.