Those chicks look older than five weeks to me...they are completely feathered out which is usually six weeks plus...that may be the problem - a bigger difference in age than you thought...
The delaware/light brahma (red comb) and cuckoo marans (red wattles) in the first picture look like roos to me...also the two barred rocks in the second picture (combs plus double barring - lighter color than females). The two red ones look like pullets so far. The (other) light brahma has a pullet comb and rooster feather coloring? Plus the slower feathering in a larger breed often means male. idk about that one...