I'm not rigid about my recipes either. If I'm short of something, I sub something similar. If I want to try another type of oil (say high oleic sunflower in place of olive), I try it. Sometimes the experiment doesn't work out as well as I'd like, but more often the soap is fine.
To a large degree, the quality of soap isn't controlled by the fats used ... it's controlled by the fatty acids contained within those fats. In general, my goal is to keep the fatty acid profile within reasonable ranges based on my experience with how my soap has performed over time. I'm reasonably flexible about the fats I use to reach that goal.
I would never want to create a "perfect" recipe or set of recipes and adhere rigidly to them. Not my style ... nor do I think that inflexibility is necessary to make good soap. I also think most people, including me, have quite different perceptions about what a good soap is like after a few years of experience. Many beginners, for example, want to use fancy (and expensive) butters or only essential oils, etc. For many people, those expectations do not last long, as they learn more about the costs, availability, and performance of these ingredients. And many beginners do not fully appreciate the importance of cure time on improving the quality of their soap.
Furthermore, I'd say the use of some fats might cause soap batter to trace a little quicker, but honestly how a person makes the soap has a huge influence over the working time as well. So I wouldn't rule out certain fats just because other people say they accelerate trace. Rule them out after you've tried them and learn how they perform for you.
So my advice ... don't get stuck on nailing down every detail at this time. You're a beginner and there's a lot to learn about the general techniques and mechanics of soap making. See how various recipes perform in your shower and hone your preferences based on personal experience. Don't shoot for perfection as you understand it now, because your idea of perfection is going to change as you gain knowledge.