Actually, with Monkey Nuts, the chainstay length of the KM would be 17.55" only 0.55" shorter than the LHT. The wheelbase would be 0.95" longer.

The KM was wisely given a lower bottom bracket to compensate for the larger, higher profile tires that it can accommodate.
Converted to metric a 2.35 tire is about 60mm. A knobby has a higher profile than a smooth tire due to the knobs. The BB drop of a size large KM is 2.7 verses 3.1 for a 58cm LHT. I think the larger tires could make up the difference.

Would I want to tour on Big Apples? Yes, they ride wonderfully.
They roll fast even at low pressures and at low pressures they have tons of grip and a comfortable ride.

To me, the advantage of the KM is that it's a 29er mountain bike. It would ride better on trails than either a 700c LHT or a 26" adventure touring bike. 29ers roll over trail obstacles better and are more stable when leaned. Gary Fisher has said that he's much better on a 29er and that he would not go back to a 26er. The head and seat angles of 29ers are more similar to road bikes than to 26er mountain bikes so they would ride well on the road too. With fat 700c road tires it would have to have the most comfortable ride of all.

I agree with the advantages of the 26" wheel in developing countries.