It's not so much that you're not going to buy a bunch of different firearms so no need to take the actual course. The thing is, you need to be familiar with whichever firearms they will be using for the practical exam and that is were familiarity with the guns is important. You can't go into the exam and ask "Oh, where is the safety on the lever action?" or "How do I release the action in this pump action shotgun?" and how the examiner expects you to know the steps to cross a fence etc. You are required to know these firearms like they were your own even if you think you will never buy a lever action, SAA, hinge action etc. etc.
If I'm not mistaken, most instructors end up becoming your examiner and if they are picky, they like things done "their" way. Not like they're out to fail you but make enough hiccups and you'll be rewriting.
We're not trying to "bully" you into taking the full course. We're just going by they type of questions you are asking and pretty much everyone came to the same conclusion that you are still pretty green. That's some of the best times when getting into firearms because there's so much fun learning going on. Being academically smart is one thing, having practical knowledge is something you gain from hands-on experience so don't take offense when we suggest you take the full course.