i don't have any historical text about anything MA related, 1) for the fairly obvious reason that it would be in chinese, 2) its authenticity would be impossible to verify £ it would give no insight at all if a weapon was useful or not.
however from an engineering standpoint, there no reason at all to articulate a weapon if that articulation makes it less effective as a weapon, Other than 1) its to facilitate carry or transportation or hidding, much as a pocket knife has a hinge to make it easier to carry, even though its use as a weapon is reduced or 2) that its some common farm implement that people may have available that they decided to weaponize, much as rice flails were weaponised, which also have the advantage of easy carry over a straight club.
As its a really bad weapon if you have any choice at all in which weapon you can choose its probably best to put it down as anachronism, and not waste to much time wondering why they choose such an inefficient weapon to practice with and certainly not waste time learning it yourself, that would be foolish.
as a pointed out to my instructor when he wanted to teach me how to use a bo staff, what possible use could that ever be to me, it would be better to take up knitting as at least i could get the needles in a lift or a toilet cubical