Need to resolve a trouble with a logic pattern in an CR assumption

You are looking at the wrong pattern, but the pattern of this question will be repeated on the GMAT.

The pattern is that an argument will state something, for example, as you said, "The reason for problem X is lack of Y."

Then question will ask what assumption the argument is based on.

The correct answer will somehow CONNECT X to lack of Y.

In this case the connection is made via the assumption, "Sufficient Y would solve problem X." In other words, if you are saying that the reason for X is lack of Y, then you must be assuming that sufficient Y would solve X.

Having said that, if you see stated as fact in an argument "The reason for problem X is lack of Y." logic dictates that holding other things equal, sufficient Y would solve X, but if other things are not held equal, sufficient Y may not solve X.

There are two takeaways here.

One is that prethinking answers can slow you down and/or obscure the right answer or, worse, lead you to the wrong answer. I personally place little value on the whole prethinking thing, but in any case prethinking may be a good way to focus on and understand an argument more than it is a good way to find answer choices. The right answer choice to most CR questions could be pretty much ANYTHING.

The second takeaway is that for doing CR questions there is no substitute for seeing clearly the logic of what is going on in the prompts, questions and answer choices of each unique question. In other words, just as you need to be careful about using prethought answers, you need to be careful about seeking to apply the pattern of one question to another. Yes there are certain patterns that show up repeatedly in answer choices, but once you get beyond certain simple patterns, the nuances of each situation could differ. So be careful to fully understand the logic of what is going on.