I can believe they are Marans, just not show quality....and not French line as no leg feathers. Legs may be a bit too dark, which can be lack of control in the line, or its simply the photo lighting. SOP calls for light to mid slate, BCM can be dark slate.
The top and the bottom are definitely roosters...you can see the red bars coming in on the wings. The top is likely a Blue Copper. The bottom, I'm not sure....Marans come in a number of colors, and breeders often like to try for some designer colors creating some unique patterns...sometimes crossing over a Wheaten or Buff with something else like a Blue Copper can give some different results....or they may have been trying for Gold Salmon. That bird might be a mixed breed or a mixed result of coloring attempt (and reason for sale).
The middle bird looks Black Copper Marans, and is likely a male due to comb size at 3 to 4 months of age(?), however it does not have the red bars yet, and one of my pullets matured quickly and laid early...so there is a little hope this might turn out to be a pullet...but prepare yourself for male.