[Kijin]

So... Fairly new at this thread thing, but a friend introduced me to this discussion and I had to add my two cents.
I've been training in Jujutsu (a form of martial arts centered on grappling, taking down opponents and keeping myself from being taken down, all while using the most minimal amout of personal effort possible) for about ten years now. I've trained with many people from various age groups. My dojo holds childrens classes for kids 4 and up.
If you think one day of teaching them to be organized will make a difference, you are sadly mistaken. That being said, I've worked with the kids on a fairly regular basis. We play some games with them when they're good, including 'keep the adult on the floor'. we lie on the floor on our backs, and their job is to keep us down.
Agreed, they don't get to punch, kick, scratch, etc, but neither do we. and it's no challenge getting out from under any 5 or 6 kids in my dojo.
If you gave me the ability to start standing up, and do whatever I needed to to keep these kids away, I could easily do it all day. I'm no big guy, 5' 10", about 175, but you need to realize that even with hundreds of kids, they can only come so many at a time. and when you use one to take out another two, that limits them further. kids heads are very hard. If you grab one by the ankles, he makes a very feasable blackjack. My feeling, therefor, is that an indefinite number of 5 year olds is nearly irrelevant. the breaking point would be when I got bored.