Although your rabbits are quite lovely, I doubt that they are Flemish Giants. They appear to be Continental Giants . Pure breed Flemish typically are between 16-21 lbs. Although it's not unheard of for a Flemish to get to be 24 lb that is not typical...and yes 16lb is a nice size rabbit especially since this one still has 6 months of growing to do. Quality rabbits are also bred for several standards and not just brute size.
Look up continental giants and see the difference in the size of the heads and ears compared to flemish giants. You also won't find many breeders of Continentals in this country because it is difficult to get them brought over, to my understanding, I know there are some Flemish breeders that are mixing continentals into their flemish lines but that is not highly regarded among most breeders. In fact one of my does has continental in her, but she is not one of our show rabbits. She is a pet and her babies are pet quality.
I think its great that you rescued these rabbits from an Asian Farm Markets you can't compare a continental to a flemish. Its like apples to oranges.