再问OG89

There is now one microcomputer for every thirty-two pupils, four times as many as there were (microcomputers for pupils) four years ago.

那比较的仍然是ratio, 那是不是应当用as high as而不用as many as呢？

另外，如果as many as 在这里确实是表示具体数量的比较，那前面是ratio(one microcomputer for every thirty-two pupils), 后面变成了具体数量，比较对象能有可比性么？