What I think this thread is really about is what should the priority in training be for a person interested in self defense. This need to prioritize is important given that most of us have limited time to train, limited opportunity to train with really good instructors, and a limited training budget. There obviously will be exceptions, unique circumstances, etc and it should go without saying that no one size fits all. That said here are some of my thoughts on the issue. If someone took a real interest in self defense and wanted to start from the ground up I would suggest the following:
1. Start working on strength and conditioning.
People generally don't want to hear this one. First of all it doesn't let you buy new toys or cool gear. Buying a new gun is more fun than doing burpees or running sprints. You cannot buy you way to an acceptable level of fitness. It also for most people isn't that hard to achieve. It just takes commitment and work. I place it first because being in decent shape enhances everything else and makes learning other things easier. Sucks to go to the shooting class and be so shot after a day that you cannot maximize days two or 3. I've seen that. Furthermore, a lot of self defense is fighting and a fight is a physical thing be it fighting unarmed, with an edged weapon, an improvised weapon, or a firearm.
Strength and condition can also be worked to into drilling other skill sets. Getting up and down from prone is like a burpee. Sitting up from supine is like a situp. Taking a knee is like doing lunges. You can build reps of those skills while getting some work in.
Hard workouts also develops mindset which really matters in fighting. You don't have to start crazy or go beyond your limits but start conditioning. Conditioning also has a short shelf life so it needs to be done on an ongoing basis.
2. Basic safety and gun handling:
Its axiomatic that one needs to understand how to safely handle a gun and operate it before one can train to use it or carry it in defense. This would include the four rules. Knowing how the gun works, how to load, unload, operate its various controls etc.
3. Basic marksmanship:
Things like sight picture, sight alignment, TRIGGER PRESS, grip, etc.
4. Basic defensive gun handling and shooting:
This would be the material you get in most basic hand gun courses. Things such as drawing from a holster, slide lock reloads, tactical reloads, clearing various malfunctions, doing the same strong and weak hand only. It may cover shooting from some basic positions and perhaps some degree of movement.
Besides learning the basic skills this is often a good way to sort out equipment. I've seen people at basic classes realize things like: my holster sucks and is an impediment to me, carrying my magazine there sucks and is an impediment to me, I can't shoot this tiny 380 nearly as well as the people around me are shooting their bigger guns, etc.
After getting good instruction practice, practice, practice. Much of this can be done without the use of live fire. One needs to drill this stuff until it is automatic and smooth.
5. A more advanced shooting class:
Often will get more into movement, use of cover, various shooting positions, more demanding drills, etc
Some of these may be specialty classes that deal with skills and tactics in and around vehicles (such as Viking tactics street fighter, or HSP darkness vehicles.)
6. Force on force/Close range classes.
Most people don't get to this step and they as a consequence never learn what they don't know. These classes open peoples eyes to the potential physical nature of fighting for your life. The tend to integrate empty hand, edged weapons, and firearms. A firearm is not always the best tool or the right answer. These classes can be eye opening to the danger presented by an attacker with an edged weapon. Class like this tend to be more physically demanding. They also tend to get down to the nitty gritty of the types of threats one is likely to encounter and needs to be able to deal with. I have in mind classes like those offered by Shivworks. Classes like this drive home that there is a difference between shooting and fighting. There is also a world of difference between static shooting on a single lane square range and training to fight with a gun.
That is just the gun stuff: If someone wanted to address all facets of self defense. And the reality is there is interplay between all of them IMHO. I would also suggest the following:
Get some basic Brazilian Jiu Jitsu and wrestling skills. A lot of the Shivworks stuff is using BJJ principles and applying them to real fighting, fighting in different environments like a car, and the presence and use of weapons. Sport grappling is not the same as fighting. However, someone that has a BJJ blue belt is light years ahead of someone who doesn't and can much more easily apply the principles to these new aspects.
Get some basic Muay Thai skills. In the absence of decent Muay Thai I would go with boxing. Most of what I said about BJJ applies to Muay Thai. If someone is interested I can explain why I say Muay Thai specifically. This is a great way to do start working on number one on my list as well. When you can condition and build skills at the same time its nice. I would start the Thai/BJJ right at the very beginning if I really was serious about self defense. By the time you work you way to the force on force and close distance type training you can have a great foundation and IMHO will get vastly more out of that type of training than someone who is just rolling in a weekend class and being exposed to any of it for the first time.
Do some edged weapon work. Most people totally underestimate edged weapons. Quite honestly I would much rather have someone pull a gun on me inside of five feet than a knife.
As that list shows there are a lot of things to learn and it takes time, effort and resources. There is no magic way around that. Now plenty of people defend themselves with a gun who have never done any real training. Just like people win fist fights that have never done any real training. Most people face relatively few threats in their daily lives and may think that it is just not worth that much effort, time and money. I'm not going to argue with them. For someone wanting to be as able as possible to deal with likely threats and who intended to carry tools to deal with them that is the basic road map I would follow.