Reflex.

My Son got a new set of focus mitts and punching gloves and it just so happened to be the day my Brother was visiting.
He definitely wanted in on the action, waited until I was completely focused in working with my Son on some drills in the driveway, snuck up and put me in a half-nelson-type hold saying to my Son, 'You see this! He doesn't...' the next thing he knew I was twisted out of the hold with my fist in his face, pure reflex.
He had meant to say that I don't surprise easily, but what he fails to understand is that I am surprised every single time it happens, I just have a good flinch that takes care of the rest.
In the words of Jack Burton (Big Trouble in Little China) 'It's all in the reflexes.'

That is the difference between thinking 'step and turn, then punch,' and just 'Smash in the face!'
We shouldn't be focusing on learning all these different techniques (especially when there really are only a few techniques with thousands of variations), no, what we need to focus on is the 'switch' or as Rory Miller calls it, the 'Go' button.
These should also be in-line with natural reaction, the fact (and I have seen it first hand both on the street and in the Dojo) that trained fighters become worse while the untrained tend to become better under pressure.
Does that mean they are doing something different? Yes and no, my brother does not have Martial Arts training, but I have seen him pull off movements from Kata nearly every time I have witnessed an altercation, or sparred with him, always by instinct.
The difference being that while we give fancy names and fancy steps to things he would say, 'I just grabbed and hit,' or 'your face was open so you just got jack-slapped.'

Millenia of survival oriented evolution prevails over a few years of hard work on the training floor with some good friends who are not intent on making sure you don't ever walk (let alone breath) again.
Training is, in my opinion, important, but certain things need to change, the approaches need to be complimentary to the above, otherwise you have two opposing things that will cancel each other out (and ultimately cancel you out) when the time is necessary to act.
When you step on the floor you know what you are there for, which is already working against you (though I have seem some pretty surprised faces when contact is actually made - maybe there are some people who think they are actually at a health spa??).

I like the random surprise scenarios, it gives me a chance to really let loose and see what happens (and I usually only do this with my brother and a select few people).
I can play with sucker punches at random, being grabbed from behind when I absolutely do not expect it, see what happens and mull it over in my mind afterwards - not something that can be consciously worked on in the moment when you are in a state of mental surprise, but conscious thinking does play a role in the aftermath, 'Ok, so that worked,' or, 'Ok, so that didn't work, lemme see what I could have done and train it over and over again.'
Repetition is a great friend to have, though many people get bored with it, especially in the Dojo where you are constantly line-drilling up and down the floor for hours without ever really making contact with anything.

There is also that notion that there is some standard by which we need to be working in order to seem 'authentic' in what we are imparting.
That is well and fine, some things are going to look similar on the surface, but no such standard exists, and holding on to some standard or looking to some higher authority for the correct way of doing things has just effectively taken responsibility out of your hands - at least that is the illusion under which most of us tend to live.
I've been in some pretty bad areas, some pretty bad situations, my Sensei was not there to help me out, it was only myself, the other guy, the pavement, and whatever else was around.
No one is going to hold your hand through these things, no one is going to say, 'alright now darling, you're going to be alright,' unless you find yourself in the Ambulance afterwards with a bunch of EMTs trying to keep you alive. No, this is about taking on responsibility yourself, the only one you can trust (and the only Teacher you really have) is yourself.

People can show you different ways to do things that may or may not have worked for them (in theory or in practice, whichever, most often in theory), but they cannot apply it for you (and they are equally responsible for the image they portray in what they pass off as 'effective').
I'm also not saying that these Guides are not important, those that are the real deal are out there and definitely worth listening to and respecting.
They will also not foster some delusion of a 'mystical' death-touch-type technique that will be an end all - the fight stopper is not some magical technique, or age-old secret teaching, it is less physical than mental.
You want to get it done, get him down, and get away, however you do that, if it works, that is the only measure of correctness - you do what is natural, what is within you to do, not what someone else tells you to do (in the end you are the one that has to sort fact from fiction, no one is going to do this for you).

So how might training be changed up in order to accomodate the above? Some might say not at all, and perhaps this works for them, that is fine.
There are some aspects I like and some I do not (mainly because they have fostered some really bad habits and ideas), perhaps this is more of a personal bias, but I would rather trust myself in the long term and I would rather have those that come to me for guidance trust themselves.
Maybe they take something useful, maybe not, it is less about passing on a 'style' than it is about passing on a 'spirit' or a 'mentality,' even then, what is really passed on was never really passed on when the dust actually settles.
I've said that before, I know, but even working with my own Son I realize that some things are universal because of the Human Body, the mentality is a different beast entirely and that is really what we are dealing with (and often what is lacking in many mainstream Dojo, Gym, and Training Hall).

When surprised my body acts, it may have seemed that I am not surprised, that I just went with it, but the fact is, I was surprised, just as much as people who seem tough as nails are scared on some level, so they fight harder.
I don't even begin to understand the cog-work behind some meth-induced frame of mind, it is just as well to know it is there and to understand that it is not going to be nice to you or treat you in the same way a training partner does.
It doesn't care if you are able to keep on going to your nightly training sessions or get up for work the next day - it just doesn't.

There was a similar movement I did with my brother where I spun around, stepped in and tapped him under the rib-cage with my hand, under his arm where he could not see it, 'Now imagine if I'd had a knife, even a small pocket knife.'
Yeah, that got the gears turning and put him in the frame of mind to think about it, like he needed to, perhaps that was a mistake on my part - hopefully he doesn't get stabbed because he over-thought the scenario and became stuck in some mental loop.