It's important to remember that the legal system isn't perfect. It's just more perfect than the known alternatives.
Trial by combat was no joke. It was the process for centuries. It presumably had the virtue of resolving disputes in a manner short of war or century-long blood feud, and its obvious bias -- toward the better fighter -- was, I'm guessing, a design feature: In the absence of government police, any judicial system that didn't weigh the odds in favor of the stronger party was liable to be ignored in favor of extrajudicial violence. Why take a guy to trial rather than just stab him in a bar fight? Well, if the trial resembles a bar fight, but one in which the winner emerges with a clean reputation and clean legal record, nobody has anything to lose by going to trial.
But it literally involved losing limbs and eyes, followed in short order by either the legal rights or the life of the loser. I like the lawyer system better.
I said it was a venerable history ... and like you, I prefer the wimpy modern version. Less interesting as a spectator perhaps, but much to be preferred as a participant.
Any type of trial is based on the notion that the outcome will be Fair and Just. What people consider Fair and Just changes depending on the people and the time; in some communities simple consistency is apparently enough...
Having now revealed my relativist leanings, I will point out that there are certain politicians and telemarketers that I would like to subject to that other time honored judicial fiction, er, system: Trial By Ordeal.
The trick will be finding a pond big enough and a large number of heavy stones.
Seriously, though, before you can defend against a strategy, you have to recognize and understand it.