The staff is usually taught first because it is the least likely to injure the beginner and also because the way it is held, it mirrors the empty hand forms, with one hand extended and the other chambered and the foot work is identical.
One way to improve the staff routine is to practice at full power without it, this will also improve your empty hand forms. Also break up the routine into parts and work on your weak areas over and over again, like learning a musical score.
The reason why weapons are taught after the empty forms is because of the need to have good foot-work. You can never be good at weapons if your foot work is still clumsy and do not provide a strong base which is essential for issuing power. And because weapons are done at greater speed, stance changing gets more difficult.
I'll rather be happy than right, anytime.