EldritchCleavage And Sharia is no older than 1400 years old, if my rough reckoning is correct. The English common law still cites statutes and cases that are hundreds of years old, we should remember. Not defending Sharia (which holds no charms for me), but the contrasts between it and our common law in particular are not as great as one might think
if Sharia law is only that old, it really is even less impressive than I thought. Roman law is 2000-3000 years old and contains far more advanced principles, which is why many European systems used it as their basis. Even the Danelaw was more advanced in its administration of justice (in that it recognised formal composition of local courts) and principles than many elements of Sharia law.
And of course English common law has been constantly updated since then, by legislation and case law. I am not aware of any judicial precedents dating from earlier than the 1600s which comprise law today, and those few which are that old are very compatible with modern thinking.
The contrasts between Sharia law and our modern legal system are huge. Thankfully. A more realistic comparison would be if we were to use our bible as our legal code, and bend it to fit every modern situation, and allow it justice to be mainly administered by religious church ministers, rather than qualified lawyers (I admit that some clerics in charge of Sharia law are legally qualified on occasion).