I've just finished prepping for and started giving some guest lectures on the application of training for a local college's Exercise Science Department. Particularly, I'm giving lectures on the application of periodization, and implementation of weight training, plyometrics, and speed/agility for athletes. I don't know how I really ended up being in the position to teach on these things, but I have.
In my preparations, I dove more into these applications myself to help bring together the world of science and practice, and was reading books of pure scientific research and of pure anecdotal experience. This included Bompa & Buzzichelli's "Periodization Training For Sport," Louie Simmon's "Westside Barbell Book of Methods," and RA Roman's "The Training of the Weightlifter" (the Soviet training methods).
In those readings, an interesting point comes across: each one believes that their way is the best way to train. Each author concludes that the best way to train is through their approach and methods they are writing about. They even have data to prove it.
The crazy thing, all of them are right!
When we look at training methods, or training systems as a whole, there is one thing that must be accounted for and considered in each: the individual carrying out the training plan. A solid training plan is one that is planned for, precise, and considers the confines of an individual's abilities or their development.
The way I see it, is that coaches provide roadmaps for individuals to meet their goals. There are multiple roads that can be taken to meet them, and due to the factors that will undoubtedly arise in training, no road is a straight line from A-to-B. This is where different methodologies can still all be the best training approach. One may take a little longer than the other, but will take less effort on the side recovery. One may get you there quickly, but require a greater emphasis on precise nutrition. These things are all individual.
When we look at training methods, we shouldn't look at which one is "the best" as a whole. We should look at which is the best for us (or the individual we work with if you're a coach). Ultimately, thought processes and a system's way of thinking will always beat a single system.