Some people say the world is getting to be a very dangerous place, other people say the world is actually getting safer, but has it ever really mattered what other people say to begin with?
If you get lost in the woods on a hike tomorrow do you know what to do in order to survive? Do you know which plants you can eat, which you can use for medicine, and which can kill you?
There is a plant called a Water Hemlock, which is related to the Poison Hemlock that was used as the method of carrying out the execution of Socrates (also a Martial Artist), and it is among the deadliest plants in the world.
Do you know how to identify it? If not you may want to take a few moments and find out, just to be safe when drawing water from any old drinking hole into a cantine.
What is my point in all this? Awareness. Being fully aware of what you do know, and what you don't know. What your limits are, and training to eliminate those.
Many people, when they think of 'Martial Arts' or 'Budo' only think about certain things, some sort of preconception they have been conditioned to picture in their mind's eye, white Gi (or some sort of Kung Fu outfit), little old Mysterious Asian Guy who can kill you with his pinkey finger.
The image of picking plants in the wilderness, hunting, Shotguns, Rifles, Handguns, Fatigues, proper cleaning and butchering of an animal, knowing the difference between good plants and bad plants, making a shelter, awareness in a crowd, or even the image of Socrates... These do NOT come to mind for most... At least not all of them, some maybe, but not all.
Most like to think their 'system' or 'school' or 'Teacher' has all the answers and they feel they can rest easy knowing this, and there are quite a few Teachers out there that would encourage this sort of thinking, this sort of Blind, Cult-Like Faith.
The fact of the matter is that if a Teachers says you do not need to know how to Grapple then they do not know how to Grapple, if a Teacher says you do not need to know how to fight standing up, then they do not know how to fight standing up... A great Teacher can admit their limitations and, if they have not worked those out, they can point you in the right direction to help you out in those areas.
Karate CAN be used in Ne Waza, or Ground Work, and Brazilian Jujitsu CAN be used in Stand-up, however, it is the focus of the individual that determines the use (and just how effective their application of either will be).
Can either of these tell you which plants are okay to eat in the wild? No. They can't teach you about Gun Safety either, nor can they teach you to shoot.
So within a certain context, sure, they are flexible, but only within a certain context.
Kris Wilder Sensei once told me that the best thing about being Independent of any Organizational Heirarchy was that YOU determine what is permissible in your School.
If you want to invite someone to come in and teach a Knot-tying Seminar or a Binding and Securing Seminar then you can, you can also partner with people who can take your Students into the woods and teach them something about tracking, learning which plant is good, which is bad, whatever is available, and whatever they wish to pursue.
My Sensei once told me that a Budoka's aim was to achieve the formless form, free from all forms, an expression of the essence of principle beyond it all, yet through it all, bound by nothing and using former bonds to help others reach beyond them.
Not his exact words, but the point was clear, or at least the point is clear now.