In The Concise Oxford Dictionary, a system means a complex whole, set of connected things or parts, organized body of material or immaterial things; the established political or social order. In modern times almost everything we do seems to have a system or a connection to systems in some form or other. But systems tend to break down if connections are lost. (Think computers)
Or invariably when a system is not properly implemented or followed through, things do not work well out as expected. Therefore it is necessary to have a proper guide or coordinator for the smooth implementation of a new or existing system and one who can rectify or improve upon it wherever required. (Banking system, accounting system, tax system, computer system, etc)
In war, The Art of War remains a great system for generals during the Spring and Autumn era and arguably down till today. With or without teachers, those who truly understood its thirteen chapters thoroughly and had properly implemented the system in wars; achieved great success for their states or countries. Think Sunzi/Han Hsin/Cao Cao/Mao Zedong/General Vo Nguyen Giap. The last two named modern leaders, Mao of China and Giap of Vietnam, employed guerilla tactics to great effect to wear down and demoralize better armed and larger enemy forces that they faced before finally emerging victorious.
Can the same reasoning be applied to The Way?
Obviously the same reasoning can apply. If we reread the Tao Te Ching in detail, we may find that Laozi seemed to have written an entire system in the Classic on how to cultivate and return to Tao. A system made known by Laozi and in an almost similar fashion by two other great sages, Confucius and Buddha all circa 2,500 ago.
The TTC is actually quite well structured if we analyze and understand existing religious Daoist practices taught by immortals, and not allow idiosyncrasies to set in. Similar to military leaders not able to fully grasp the Art of War, Daoists may not have thoroughly understood and/or correctly followed what is written in the TTC. It could be too profound or some do not have the required learning or practice. When we misunderstand what Laozi meant or chose to follow seemingly easier bypaths and our own idiosyncrasy, the system purportedly breaks down. Without fixing or repairing our understanding we may continue to tread onto bypaths just like what Laozi, Confucius and Buddha had said. Please refer to the TTC, Analects and Dhammapada if you are not too particular about different doctrines and/or religions to expand your studies of the system.
Therefore it is often recommended by past masters in Daoist texts that we seek out real teachers (which may include Daoist immortals) to correct or fine-tune our thoughts and to guide us through the practice in order to return to the Way (Tao). With earnestness and sincerity, Daoists, Buddhists and Confucians can still benefit much from a clear and continual practice even if they do not get to the Centre of a great system!
Meanwhile fellow travelers and I plod on along the far journey none the wiser whether we can ever reach the final destination.