Hi gastoneMIT,
That type of plan is problematic for a couple of reasons. First, it's going to be difficult to hit a V33 if you're only focusing on one of the 3 question types (RC, SC or CR) and essentially 'guessing' on everything else - there's just not enough points in any one area for you to hit the 68th percentile. While you would probably pick up a few correct answers with some lucky guesses, you would likely fall short of that Goal. You could potentially hit that Scaled Score by focusing on two of the 3 types (and quickly guessing on the questions in the third category). However, we then run into the second issue: how exactly are you going to guarantee that you will correctly answer all of the questions that you choose to focus on (since that would be an essential component of your plan)?
You can hit a V33 without being 'great' at any of the 3 question types - as long as you pick up enough points overall. With decent overall Verbal skills (meaning that you know how to take proper, organized notes and you understand the patterns behind CR and RC - and you know enough Grammar for SCs), you can bypass all of the hard/weird Verbal prompts and focus your time on all of the 'gettable' questions in all 3 categories.
GMAT assassins aren't born, they're made,
Rich