Very interesting take on the verse. Nature is "wild" and without actual decision, except in the case of a predator acting on impulse. That is more instinct. Nature is many things, mostly untamed. If I could correct the translation I would go for a more eloquent word "instinctive" instead.
Some of Chinese Martial Arts can be like that if you have a decent instructor, once your internal viscera have been strengthened enough. That is not an advertisement for learning martial arts. On the contrary for some learning even the littlest thing makes them way over confident.
Straw dogs are vessels, shells. Straw is seen as small bamboo (bamboo is said to be like man, the spirit within), dogs are but clumsy and loyal to a fault. So although we all are straw dogs, our physical bodies are shells.
Nature is many things. Long and varied learning is only useful if practical.
By learning that nature itself emits certain magnetic fields (and I do not mean chi by what I say) one can learn to strengthen this field inside ones own body. This can be used to strengthen the blood flow and other vascular systems. But you would be hard pressed to try to teach it to yourself, and most people would have a hard time teaching anything to themselves due to their own paranoia or overthink.
