aggression can come in different forms for different dogs. It's tough to define, for me, it's one of those things you learn to identify with experience. I don't like to use prey and defense, because I think those are pretty vague terms and there can be lots of confusion using them.
Dog training is easy with experience, but complicated too. For me, a dog can have a lot of prey drive, but very high thresholds to stimulate those behaviors, and defense? that is for when they feel threatened and what most people call "aggression",but some dogs, Mals especially have a lot of prey aggression too.
For me, nerve strength and thresholds mean a lot more to me than what "drive" they're in. Some dogs will go into "defense" very easily, but have no nerve to stay in the fight. Some dogs have such strong nerves and high thresholds you have to push the dog so far to get even a tiny bit of real aggression it's not worth it. It's too hard on the decoy/handler
Some dogs have ton of "prey" drive, but have no nerve to come and get it when the "prey" is cornered, ie the blind or on re-attacks (drive switch to defense) Some have poor nerves, but such high prey, they cant' help but come and bite, even though in their mind, they want to run.
We don't do table training. I've actually never met anyone that has. To me, if the dog can't do it with 4 legs on the ground, they have no business doing it anyway. We do use tables to teach positions and do OB stuff on them, but that's entirely different.
I'd say the people i've trained with most vary pretty widely in how they train, but most of their training is based in motivation, but some will use e-collars or pinches for corrections, some will put their dog up and stop the fun, some can use mostly all verbal, and pretty much everything in between at some point. Honestly, there isn't a lot of difference in the end products if the handler is competent in what they're doing. I have never seen someone not use a "correction" and train the dog to standards I think they should be at.
To a lot of people, it's just a way to go have fun, and it is for me too. In fact it is my number one priority to have fun with my dogs. But at the same time, it's a test, or it should be. Dogs and handlers need to be pushed, they need to be tested, and sometimes it isn't always happy fun and pretty, but when pressure is applied it is also taken away. In the end I think it makes a more complete dog and a more complete test of the nerve and strength of the dog. Physical corrections are a part of that and they can be used in positive ways for the end product considering the handler knows what they're doing. I've also seen yahoo's that have no business handling any dog, let alone a fine working dog, and you can see they're a moron in their work. The dogs dont' lie, you can tell what someone is doing to them just watching them interact.
and most importantly, schutzhund or any of the ring sports aren't something you learn in a few week class and get a certificate. it's years of training to get it right, and that's just with one dog, then you get another one and everything is different
But it gets easier, you make less mistakes, but you still make new ones even if you're smart. If not, you just keep making the same ones over and over again
I've seen a few have success early, some because they were more natural in their understanding of dogs, and they got a good dog to start, but usually, it takes a lot work and experience to get good at it, but that's like anything i guess.