The broad sword is more of a 'battlefield weapon" because of its hacking ability as opposed to the jian (at least for the past 300 years, or so), which may be for the scholar, the officer corps and others. The jian may have retained martial utility but it is not for the 'battlefield' as the Dao was!

The Big Sword Battalions were broad sword based so their function was already made by the actions of the common soldiers.