It's actually stupid for the writers to have any GL or even Amazo to suddenly gain Superman's powers just by copying their dna. This is because it took Superman many years (at least 16) of absorbing enough solar energy energy to have any significant powers. Now in the movie, Superman is able to instantly have acess to his powers the moment he is near an atmosphere with one yellow sun. But the comics are entirely different. Also in the comics, it even takes a long time for Superman's energy to deplete when he is away from a yellow sun. But not so in the movie.