I will give you continual homage if you can show how any type of fender will keep your bike frame and drive train DRY in wet weather.
Given the fact that only so much water will stick to a given sold surface and that once that threshold has been reached you loose. Lets say a two hour long ride in a light drizzle and completely soaked ground.
I am not saying fenders don’t work to protect the rider from getting sprayed with what is shed from the tires but the OP is about how water will affect his drive train.