the better the school,the more help[ful the students.这个句子正确吗?

the better the school,the more help[ful the students.这个句子正确吗?
按规范英语，这个句子无疑应该写成：The better the school is,the more helpful the students are.或者：The better the school is,the more helpful to the students it is.但有人认为在广告或格言中，上面的句子可以省略为：The better the school,the more helpful the students.我不敢肯定这样省略是否正确，恳请研究广告英语或英语省略方面的高手给予指导。