They lack the very basic causes that would create a state that could be labeled as "war". Sharpteeth don't fight for material purposes or for power, but merely for food. They don't plan to kill for "fun". Leafeaters on the other side fight to defend themselves, to live, just like the sharpteeth try to kill as many of them as they need to survive themselves. Neither side seeks to destroy the other side for good.
I do not deny that there is some organization (teaming up to fight rather than everyone for him or herself), but to call it war seems something of an exaggeration to me.
Oxford dictionary defines war as "the use of armed forces between countries or (civil war) rival groups in a nation". While I think that herds may be considered as fit for doing the part of countries or nations in LBT, it still needs some other cause, more difficult to satisfy, than food to create something like a war. Some kind of racist issue among leafeaters or hunting territory issue among sharpteeth may lead us to something more like war rather than a sharptooth's supper. Nevertheless there is always a high risk to anthropomorphise dinosaurs too much by letting them think and act the way humans would. As for sharpteeth, I don't think the larger kinds of them are likely to hunt in large packs. The smaller raptors seem to be more like herd animals, but again what should they fight a war for? Suppose that a pack of 100 raptors slay 200 other dinosaurs (thereby loosing 50 from their ranks). The result would be 50 raptors eating as much as they can but many dinosaur corpses just rotting in the sun as the raptors couldn't possibly eat us so many dinosaurs (unless they were all pretty small). So it would be much more logical for those raptors to attack and kill just one or two dinosaurs (taking almost no risk to loose anyone), eat their fill and then go for the next prey once they are done with the last. Why would they want something like a war?
