Call it what you want put violence is violence. On the very base level We come up with reasons and justification for doing what we are doing.
The term War is typically used by nations, states, or larger groups of people than smaller. The term war typically means that there is an on-going or protracted plan to dominate or incapacitate another so as you can control or cause him/her to capitualate. (or something like that). It can be as small as a gang in a city.
Wars can be fought for many reasons, of course. The key to them is that they are usually diliberate, require pre-meditation, and usually have a campaign or smaller subsets called battles, skirmishes, or whatever else you decide is appropriate for inflicting violence.
That out of the way......
Bill, I think you are getting somethings kinda tied up together.
Fights, brawls, self defense, and all that...knives, guns etc....it is all violence. One or more parties for whatever reason have chosen to commit an act of physical or mental violence against another.
It may be pre-meditated or not...
It could be a flash of drunken, hormonal emotion like in a bar fight.
There might be some implied rules, or some established rules mutually agreed upon.
Each side may have is own established paradigm about what he or she thought the rules are. They may not match!
Rules, there are always rules. Especially for soldiers in what we commonly refer to as war. LOTS of Rules! More than you care to know...pages and pages of rules. Geneva Convention, Rules of Engagement, Escalation of Force, Memorandums of Understanding, Memorandums of Agreement, Uniform Code of Military Justice...I could go on!
I think it is important to not confuse MACRO concepts with MICRO.
Geneva Convention would be an example of MACRO.
MICRO would be two guys involved in a hand to hand fight with the intent of killing each other.
At that point each is fighting for his life. Rules don't count at the moment of battle, in all cases you can use whatever means to survive. In all cases, to include soldiers, once you have rendered the individual incapacitated or unable to effect the fight, you must stop.
Same rules apply in civilian world. No difference.
I also disagree with your generalizations of BJJ, Krav Maga, and Aikido. They are training methodologiess, not defaults for fighting.
A BJJ guy knows as much about multiple opponents as anyone, so to imply that he would not be able to handle himself with more than one is not so.
Krav Maga, certainly spends a fair amount of time teaching down and dirty stuff. However, it does not have the corner on the market of lethality. Ask yourself why the U.S. Army does not train our Combatives this way, when we could have chosen to do that?
Aikido, sure it has somethings in it that are good for Bar Bouncing. BJJ has the exact same things in them, and to be honest may even be better given the closeness of people in bars for the initial engagement. Aikido, especially when you consider Jo Waza, has some very useful things in it for combat that other arts don't practice much.
I see where you are going with the Concept of MMA. Yes all the arts have various strengths that cause one to be well rounded as a martial artist.
If one were to study BJJ, Krav Maga, and Aikido they would be probably more well rounded than someone who did not.
You can also waste a great deal of your time if your goal is simply to be "combat efffective".
the secret to being "combat Effective" is to simply "train as you fight". That is, figure out the strategies and scenarios that you will encounter in combat, and then you focus on developing the skills necessary to exploit them.
difference is Timing, speed, and realism that you add to your training. Known to many as Aliveness.
The more you add, the more experience and skill you will gain, (If you can survive the training
) There are tradeoffs of course.
Once you become focused in the area, it doesn't matter what you call it or what you study, the situation drives the training and your responses and lessons learned from them become your waza.
See organizations like Tony Blauer's company for good examples of training this way.
Is there room for Budo? Most definitely, for reasons other than simply gaining "hard combat/fighting skills".
That is another topic all together though!
Enough of my ramblings.