Asuma is can be one of the best at taking out a few people very quickly. As we have seen that in times of war there are meeting of higher ups in wood shacks most of the time. Now asuma could easly make a small crack with his wind knife and then breath in burning ash. this would cover the whole area and there would be no way to live short of being a path of pain/ some god of endurance like 3rd raikage.
now asuma is an example of how to take them all out quickly. another example is muu's dust release. but asuma is better as its a less flamboyant way of killing them. making him a master in assassination