> That establishes the clear fact that only one cat is needed to kill each rat.

No it doesn't. Well, obviously only one cat is *needed* to kill each rat, but it doesn't establish that this is the optimal way to do it. As I say, the rats have to be caught first, and it seems reasonable that two or three cats working as a team could catch one mouse in less than half the time it takes one cat to catch one mouse. I'm not saying this is absolutely the case, I'm saying there's some doubt about the optimal way for the cats to get their job done.

Then again, if the hundred cats all start out with one rat in each of their mouths, then no team work is necessary.

The whole point to Carroll's argument is that the question *can't* be answered definitively -- that, as demonstrated by the amount of discussion this question has generated, there are too many factors to consider, and the answer is not altogether clear. The question cannot be answered definitively without more information.