The more profit because hired blue wolf mercs logic is weak. I think it's more like
more profit because sold more goods
sold more goods because transported more goods
transported more goods because hired more people (30 instead of 10, anyways whats the exact relationship here?)
And then the question is do 30 blue wolf mercs give better protection than 30 other mercs - could you have transported the same amount of goods using 30 regular mercs?