I also think a manservant might be very ueful in " disputes": traders might be less inclined to attemp to take "liberties" with the Dashwoods if they knew a manservant was on hand to take up their case( thiswas of course an era notorious for teh adulteration of foodstuffs by rougue traders).

I think the Dashwoods were very wise to have a manservant, even though he would have cost them more in tax, for not only would he provide security for isolated women living alone(handling unwanted callers, hawkers and pedlers etc) and be ale to tackle hard labour jobs, but would also provide in a male dominated socitey a form of insurance or "back -up" in everyday life.