Hmm, let me try to put this better...
My point in bringing up boxing is that we can see from the stats that a single attack actually has only a very small chance of connecting.
Well, if you only train withat single attack (which is what is pretty standard in conventional Aikido), then you're stuck. Yes, the same principles apply, but I think that it's a pretty big leap to make on the fly.
There's nothing wrong with throwing your attacker down (as you mentioned in another post), but the same problem applies. If you look at Judo or other grappling arts, you can see that only a small percentage of throws actually go to completion cleanly.
It's a similar problem, IMO.
So these are stats from competitive sports situations where two evenly-matched opponents agree to fight by a certain set of rules. I think it is important to not train with that mindset (unless you are a sport fighter). Aikido doesn't fit very well there, in general, and you aren't going to have an evenly-matched opponent mug you according to a set of rules. When under duress, you revert to behaviors you have burned in. That's why I think it is good to have a core practice where you receive a single strong attack and practice dealing with it as though you will die if you don't get it right.