Gant., Thaks for sharing your insights. Sounds like you were completely focused on your technique, instead of just knocking out the workout on the board… giving your movements full attention, you were moving through the water with efficiency, and speed was developed! You were totally immersed in swimming technique,instead of just time as your focus, and your times improved! Replacing generic workouts with workouts that were focused on your technique, specifically designed for you to improve. It took a period of time to accomplish, but everything came together! Congratulations.
Now, not sure which Ledecky event you studied or how you came up with the Hybrid label. If you analyze swimmers’ style, you will see the same swimmer using different techniques (stroke length, tempo, kick timing, etc.) depending upon the race distance and conditions, including Katie Ledecky. Look at her form in the 800 v. shorter distances. See the difference?
Having studied the Total Immersion system of swimming, I have discovered it is just what you are describing, it’s the method, the focus, the movement that makes the difference and leads to speed. It doesn’t happen over night, with one weekend or even a week of practice, as you found. Improvement takes time, as you found. Why reinvent the wheel? Someone has studied it for decades and brought it to us. Look into TI and see what you find. I am a different swimmer and have applied the system to other aspects of workouts too… Good luck!