Develop your case using language from the jury instructions so jurors will know what you're talking about when they deliberate. All the defendants are shirking their responsibility. They all point the finger at each other. Make significant and frequent reference to the logs. Use charts and educate.
Safety is always more important than cost.
The case involves expectations. Does one expect defendant to know what they are putting in those engines. A blade that shatters is unreasonably dangerous. If I knock you down I am responsible for your bruises. This turbine shouldn't fail - its like brakes on you car.