Hikermor: I don't know anything about chaparral. In my experience, slow-growing tall trees tend to be better, though not always. Slow growth means tighter grain, and the species of the tree would be important, too, obviously. I don't know what people are looking for in a walking stick. For weapons, I have a strong preference for a particular species from a particular part of the world. But it's already over-harvested, and the quality is going down because the trees are getting younger and younger, as the older forests are getting cut down. It's very difficult to get a good plank in the US.
Glad you managed to go on a good walk. It was rainy, grey, and wet here. Ah, my lovely Midwest!
As for layering defense, just try and draw your secondary weapon when your primary weapon breaks. Usually that's why you get killed, especially in close-range fighting. Your enemy is suddenly presented with a naked opponent, and he will double his effort to kill you before you get your backup weapon out. Fortunately, I've only had weapons fail on me in training. Even in that artificial situation, with sympathetic, or at worst mischievous, training partners, it's really hard to emerge unscathed.
What I worry about regarding engineered wood is not that it breaks. All weapons break, not to mention wooden ones. That's what they do, and you have to train for that situation, knowing that if your weapon fails on you, you'll most likely die before you are able to execute the backup plan. But the engineered wood broke in a fashion that I didn't like, and that's why I wouldn't use it.