When I did Krav Maga it was every technique is done this way
in BJJ it seems more concepts with huge variation
The variation and adjustment thing is part of all arts. Sure, you can study arts with lots of forms or kata, and people get all crazy about exactly what angle and position everything is, and if you are not a carbon copy, then you are doing it wrong. However, as soon as you introduce resistance, then the adjustments and variation need to take place. The form, kata or drill should be done in order to study the core components. Ideally, if you really have the core components and an understanding what you are doing and why... the adjustments and variations become second nature.
When doing kata / form based arts, the problem is that people forget to look deep to find the core concepts of the movements they are practicing. If you stay at a surface level, it gets very confusing and very hard to understand how what you practice relates to what you doing against resistance. Making adjustments and variations is then also hard.
When doing an art where they don't study kata / forms, but go straight to the applicable techniques... people have the same problem of not looking deep to understand the core components of what the techniques are working on. Again, it then gets confusing and frustrating when resistance is added because you never get the opportunity to use the exact drill you practiced. Without knowing the core concepts, its hard know how to make the necessary adjustments and variations.
These two types of training are really trying to solve the same problem. How to teach and pass on the core concepts in an effective manner. Some people learn one way better, some learn the other way better. No matter what style you choose to train, you need to go beyond surface level to understand the core concepts. And you need to get out of the drills and meet some resistance.
