Re: Aikido does not work at all in a fight.
No problem with your facts for the most part. However, I would not say the aikido contributes "Aikido contributes a disproportionately large share of what works in most real-world situations".
That would depend on your perspective and the situation.
I'd say yes, if you have the luxury of time/distance and or knowledge or a certain degree of control of the situation.
I'd could argue that in other situations that the techniques dervied from the asssumptions and methodology of training by aikido are completely useless and irrelevant!
so, the right answer to the question asked is this...."it depends".
I don't think you can empricially say that "Aikido contributes a disproportionately large share of what works in most real-world situations'.
So does aikido work in a fight..."it depends".