Farmer might have gotten a shipmennt of males that were sexed that way. Some look like sexlink boys... Roosters will have a stalkier build, and prominant comb and wattle development starting at about 6-8 weeks old. Females will not grow their combs till about 16 weeks old and their combs will keep enlarging till about a year old. They also have pointier hackles than females and have curved tails unlike girls. It is hard to point out with only boys and no girls to compare with. Boys also have that bright sheen down their necks and backs and wings as you can see in thoes pictures.
