We should look at current guidelines in popular literature for energy systems and physical training with a critical eye. It's an area that I've spent many hours researching and re-researching to come to the conclusion that current popular ideas on the subject in the field of strength and conditioning are probably mis-guided.
An interesting article on the topic can be found here:
Upon my review, I've found that there's actually not a plethora of objective, performance-driven research in this area, we've actually just taken what's put into text as fact from very few sources, when in fact, the information is probably not really accurate. Thus, I have moved away from the idea of blindly prescribing work to rest ratios in a one-stroke manner (i.e., training the ATP-PC system) and moved more towards trying to better understand the effects that the prescribed training methods have on performance outside of the training environment to that of competing, protecting or doing battle. This means trying to better understand the relationships between all of the systems at play while training and competing.
I think a more lucid approach is to evaluate "human" systems more so than "energy systems." In this light, current literate may provide us with a basis to begin to understand the roles of muscles and physiology in training, but these aren't the only factors. In fact, in most cases, I've found in the past that training in terms of using classic energy system models (i.e., 1:5-6) leaves athletes and tactical warriors rather ill-prepared to perform outside of the training area.