This is incorrect actually. Pay for lawyers forms a bimodal distribution, where graduates from the top ten law schools tend to occupy most of the high end of the distribution while everyone else tends to fall in the lower end.
One funny thing about making the engineer-to-lawyer comparison regarding this salary fixing issue is that law actually has a much more obvious salary fixing problem, since almost every biglaw firm pays 160k and firms don't tend to compete for entry-level hires with compensation.