instead of fewer mistakes ,there were more in his writing.more是代词,还是形容词比较级

我们可以把句子倒回来看
there were more in his writing,instead of fewer mistakes.
我们可以翻译为,他的作文里错误更多了,而不是少了.
more 和fewer在这里作为一个形容词的比较级,我们设想一下,如果是代词,那么指代什么呢,“错误”但是错误已经出现在句子里面了啊.所以毫无疑问是形容词的比较级形式