网友的质疑，有一定的道理。不过，英语有些结构属于“约定俗成”，不宜细分。否则，分析的结果会无法自圆其说。

以下是我个人的看法：

As many as five courses are provided.

【翻译】有多达五门的课程可以提供。

这是一个完整的句子。as many as five courses 整体看作句子主语，as many as 不建议细分，之后接数词表示“达到某个数量”，共同作定语修饰courses。这个as many as 看作副词用法，修饰后面的数词。类似用法类比如下：

as many as five courses

more than five courses

about five courses

almost five courses

nearly  five courses

around five courses

over five courses

exactly five courses

roughly five courses

approximately five courses

有类比更有说服力，包括more than five 在内，也是一个道理。

as many as five courses are provided

as many as，这个短语第一个as是副词修饰形容词，第二个是介词，但这样语法不是讲不通吗，副词+形容词+介词短语做名词性短语，这种结构是怎么来的，还是说省略了一些东

解答如下

(1)as many as+数词，表示多达..的意思

She gets as many as eight thousand letters a month.  

她一个月里收到的信件多达8,000封。

As many as four and a half million people watched today's parade.  

观看今天游行的人多达450万。

There are as many as 300 new products on show.  

展出的新产品不下于300种.

(2)as many as+从句，表示与..一样多的意思

They take as many as they can and leave the rest.  

能运多少就运多少,其余的只好撂下.

备注：第1个as为副词，第2个as为连词，引导比较状语从句。