Why did it make you uncomfortable? The slaves couldn't eat without land to produce food, and the land owners needed labor. Cooperation was necesary to survive. Like many blanket statements, the guide's were partly true and partly false.
Some slave owners were ogres but others knew that well-treated, healthy help produced more. By cooperation between land owners and their former slaves, food and cash crops were produced.
I am not extolling the system, but the post Civil War turmoil and upheaval, which both former slaves and masters had to deal with, is seldom considered.