One problem I've seen in myself and others at various stages of training is a tendency to become fixated on a particular target or technique when fighting. The tendency to focus on only a handful of targets and not to see the whole person. In my dojang we frequently talk about remembering how both you and your opponent have "two arms and two legs" (and a head, and knees, and elbows…) because there's a tendency to fixate on one thing to the exclusion of everything else.

One thing I'm wonder is if there are good ways to help overcome this through drills or other structured exercises (not sparring).

Are there good drills out there to train seeing the whole of the opponent and adapting more dynamically to changing circumstances?