Town Watch, useless or not?

[Omanes Alexandrapolites]

Hi,
Town Watch do, for me, have a small purpose. I prefer to use them over-peasants in cities, due to the fact that they are better fighters than cheap and lesser peasants, on the walls Town Watch can beat more powerful units than themselves, including legionaries, peasants cannot beat them, and they fight in a more organised formation with a shield - this provides them with a better defence against enemies that are charging at them and from missiles. Other than that, however, I cannot see a larger use for them.