Hm, I believe that the problem here is to a certain point semantic in nature. for some reason when u8sing the term "drill" in within the context of boxing, wrestling, MMA... most of us have in mind alive environment, i.e. the alive way of doing the drill, with the goal of learning how to deal with certain type of energy. On the other hand, in FMA and many other eastern arts, we usually think of people doing some kind of static, predetermined exchange for the sake of "perfecting" the technique. Bottom line is that drills are as useful las you make them. I'd say that the aforementioned interpretation is to a large extent due to the fact that too many FMA, kung fu...practitioners ARE actually simply adhering to the most basically formulated drills, as if they are carved in stone, and as it would be sacrilege to alter them in any way. I guess they would say deviate...
However, there are FMA schools doing quite a lot of sparring and other type of alive methodology in their training. a good example would be most Lameco instructors, and an excellent illustration is here
http://www.youtube.com/watch?v=GJlIAetbqCg&mode=related&search=
You will see Guro Agbulos and his students moving around in a manner that does not get developed from repeating some static drill or technique ad nauseum. It is obvious they have some serious alive training under their belts, which I believe is the case with many other good FMA people as well. After all, the Dog Brothers were doing their thing even before the arrival of the UFC on the mainstream scene, I believe.