First "everything in the legal system" is much, much more than "police lineups and a unanimous decision by 12 of your peers". For a start, police are rarely involved in civil litigation and even in criminal matters lineups are unusual - in most criminal cases there is no doubt who should be charged. However, this is tangential to your questions.
I am curious what kind of an impact a talented attorney could have with this kind of material?
File it as a historical curiosity. Ancient Jewish law has much less relevance to modern US law than modern North Korean law does; and since that has two tenths of bugger all I guess about one tenth?
How flawed are we really?
Incredibly flawed.
Even setting aside the possibility of corruption; court decisions are influenced by things like when the judge last ate, how long it has been since juror number 4 had sex and if the defence attorney fought with his wife that morning.
Focusing on the relatively simple matter of guilt or innocence; that is simple when compared with sentencing or damages, it is estimated that the error rate for false conviction is about 6%. Some of the proximate causes of false conviction are discussed here. Root causes go to misaligned incentives for police and prosecutors; they want to close cases and get convictions; In the words of Terry Pratchett, "If there was a crime, there should be punishment. If the specific criminal should be involved in the punishment process then this was a happy accident, but if not then any criminal would do, and since everyone was undoubtedly guilty of something, the net result was that, in general terms, justice was done." http://www.azquotes.com/quote/473109
The error rate for false acquittals should be considerably higher because of the presumption of innocence and the burden of beyond reasonable doubt, however, most defence lawyers would agree that the mere fact that their client is sitting in the box has them half convicted before the jury is empaneled.
However, none of that is something you can argue in court. The system is what the system is. How it is and why it is is a matter of politics (and historical inertia) not law.