Great example. Yeah, I fully agree that in general, the fastest way acquire a complex skill is to focus your practice on the particular components that are giving you the most trouble. That's the main theme behind deliberate practice: find the bottlenecks and concentrate your practice time on them.
I've been surprised to find that this isn't a common viewpoint. In fact, I have a long-term bet with a friend that I'll learn something faster using deliberate practice 'n stuff then he did trying to learn everything at once.
