Should schools equally prioritize teaching world history and national history?

Personally, I think spending the same amount of time teaching world history and national history would negatively affect students. 

First off, students would be under considerable pressure with this change, since they already have too many assignments and need to prepare for their finals. Some might need to do part-time jobs or have internship projects. Leaming those history classes would put too much stress on them. 

Second, it's not a cost-effective way to do this, since the teachers in the school might not be sufficient enough. The schools have to hire some new teachers and buy reference books for students. Additionally, there is a possibility of increased tuition fees which would impose a significant financial burden on students.