Your basic idea about Ali makes sense Kor, but I'm still not entirely certain to which nomadic dinosaur live could be compared to the effect nomadic live (or settled live) would have on humans. While many settled humans really stay in one place (their, room, their house etc.) without moving a lot, I'm not sure if Littlefoot and the others are similarly self-restricted if it comes to moving. They have their nests in the Great Vally, but they are not constricted by it like many of us are by the walls of their house. If we (humans) stay in one spot we usually do something that obliges us to stay at that spot (computer work, reading, writing etc.). If an LBT dinosaur stayed in one spot he or she would probably be bored very quickly and go somewhere to eat or do, or play something. Within the Great Valley Littlefoot and the others seem to be pretty much in motion most of the time. I am not sure if Ali's herd is moving so much more, though they would tend to move "in one direction" and towards one destination. Unless in certain special cases (fleeing from something or the need to cross a place without any food (a place which the herd would probably avoid to come near in the first place)), I suppose the longnecks would keep a comfortable walking pace.
I don't know which LBT character is the fastest. Maybe the fastest depends on the situation. In case of a short sprint Cera might have very good chances, but is she also durable in case of a very long distance to run or are others able to run for a longer distance? If there is tricky ground (boulders, rocks, ravines, and other obstacles) Petrie would probably be the fastest (if flying is permitted in that race).
Strangely enough races are mentioned in the land before time. At the end of the original movie already Cera challenges Littlefoot to a race and I think there are mentions in the sequels too. However, we never see the outcome of any race, do we? Perhaps this would be av very interesting element in a fanfiction?
