Whose copybook should college students buy when practicing calligraphy? Tian Yingzhang, Zou Mubai, Si Mayan?

Tian Yingzhang is a famous calligrapher in modern times. Our calligraphy teacher recommended our students to practice his Copybook for calligraphy.

But before that, I practiced Si Mayan's copybook, and I think his copybook is really good.

However, if you compare them by preference, whose do you prefer?