You could finish this game eventually without making those diagrams, but it will take you a lot longer. I wouldn't try to do this game without diagramming those two options, or at least understanding where they come from. The problem is, you won't have a video demonstration of the setup on the real test. You would have to use the rules to make these inferences. In my opinion, this is the most difficult part. Once you have a good setup, the games are not so hard.
Those two options are simply a visual representation of the second rule. Once you put a rule on paper, you don't have to think about it. It is built into your setup.
If X exports soybeans, then so does Y. If Y exports soybeans, then so does X. This is option 1.
If neither X nor Y export soybeans, then Z must. Why? Because every crop is exported by at least one nation. This is option 2.
Does that answer your question? I suppose you could do this game without diagramming those two options, but you would need a solid understanding of that second rule.
