The depth of your BJJ arsenal is extremely important. Technical expertise is a requirement in The Art, especially if you want to teach. The more you know enhances your credibility.
But there is a difference between how much you know and how well you execute. Let me share with you, some psychology:
Hick’s Law, named after British psychologist William Edmund Hick, or the Hick–Hyman Law (for Ray Hyman), describes the time it takes for a person to make a decision as a result of the possible choices he or she has. The Hick-Hyman Law assesses cognitive information capacity in choice reaction experiments. The amount of time taken to process a certain amount of bits in the Hick-Hyman Law is known as the rate of gain of information. Given n equally probable choices, the average reaction time T required to choose among them is approximately (credit to Wikipedia for the extract).
What does this mean to us? Simply put: the more options we have in technique increases our time in which to select and use them. A catalog of 100 techniques takes far more time to scan and select than one comprised of 10. Time that is wasted in this selection process poses the greatest threat to performance.
Watch any champion in their matches. You will start to see a pattern that they use the same techniques over and over with success. Most of what they use is not very fancy. They have selected a small group of moves that they feel is most effective for them and do it over and over and over. They adhere to the Hick-Hyman Law by realizing that they must eliminate any gap in time and performance that is be caused by thinking. This is one of the cornerstones of winning.
This is not to say to abandon learning all techniques. It is important to learn, experiment, and even fail with some techniques because you must decide what you can execute. Over time, you will start to see your own pattern of what techniques fit best for you.
Here is more knowledge, this time from the field of economics:
The Pareto principle (also known as the 80–20 rule, the law of the vital few, and the principle of factor sparsity) states that, for many events, roughly 80% of the effects come from 20% of the causes (credit to Wikipedia for the extract)
In other words: you will achieve 80% of your success from 20% of your technique.
Fill your tool chest. Work your technical mastery. Develop your strategy. But rely on your best 20%.
I leave you with this:
Bruce Lee famously said: I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times.