I understand "a man of his age" can be used when certain qualities are expected (or unexpected) at one's age, as in "He is pretty fit for a man of his age."
But when I google "the man of his age", as I found in the paragraph below, aside from the fact that it is not commonly used, I am not sure whether it means he behaves appropriately for his age or is a great figure of his era.
For one of his influence and wealth, he had surprisingly few personal enemies, though of course many musicians attacked the art he represented. Heine called Meyerbeer "the man of his age," and Heine as usual was correct. Meyerbeer's music, as Heine pointed out, was more social than individual.
Could you clarify which of them is right, or if the expression could be ambiguous?
Thank you in advance.