I tend to think of most training and all competition as 'unitary'. There's one definition of a win. There's one environment it can happen in. You face one type of opponent and he is limited in what he can do.
Unitary training is important. It's hard to concentrate on learning technique if you can't trust your footing. If the students think they are learning about knives and the instructor pulls a gun, the kool-aid drinkers (my word for the semi cultists who believe their instructor or system is IT) will talk about innovation, but in the end he has programmed his students to fail. By making it too complicated in the beginning to succeed, they only learn different ways to give up.
So training individual things and individual skills is important. Training them in a clean environment with limited chaos is important to learning- it is even important to learning about chaos itself. But that's what training is, not what fighting is.
Fighting is it's own thing. Chaos but sometimes with a plan; mistakes but mistakes made by adaptable creatures. Simple actions with sometimes complex and far-reaching results.
When I first started teaching cops, I knew it wasn't unitary. I went one step up for binary: "There are two basic ways a cop has to fight- either fighting for control to get cuffs on someone or fighting for his life. The two are not the same." It was true and clear and helpful and still too, too simple. It explained why people who were good at wrist locks and arm-bar takedowns at the academy were getting pummeled on the street- they were trying to use type 1 fighting in a type 2 situation.
The same thing can happen in each type of fight and mean completely different things. Imagine you are wrestling with a guy to try to put cuffs on him. (Shouldn't have to say this explicitly but by definition if you are wrestling for cuffing it means he is not trying to harm you and you know it). The threat makes space and breaks away. What do you do? Probably tackle him before he runs.
Same situation, but you're fighting for your life, down on the ground, the threat biting and clawing and wrestling for your gun. The threat breaks away. What do you do? You let him run if he runs. Access a force option, get on the radio. If the battle is for your life and the threat leaves, that's a win. Re-engaging when it was in doubt the first time jeapordizes that win.
Nice example of binary, right? But what if he breaks away to grab a beer bottle or a kitchen knife? That could happen in either of these fights. That changes everything. Binary is an improvement, but it is still too simple.
Chaos elements enter the equation. In a unitary environment everything possible has been done to limit them. The martial artists in that environment wants to develope skill in training and test specific skill in competition. In real life, chaos is always there, luck always plays a role and the longer it lasts the more chaos is introduced. Dealing and adapting to the chaos is a skill in itself, one ignored by the koolaid drinkers who already have their answer.