From my understanding, you have just one root pitch, 10 velocities, and no round-robins. Therefore you only need one group, and 10 zones:
Use Optimized to create an instrument
The Optimized setting automatically determines the root notes of the zones and maps the zones across the keyboard. If there are multiple zones with the same root note, Sampler creates velocity layers—a different sample is triggered depending on how hard you strike the key—based on the perceived loudness of the samples. Sampler finds loop points, balances the volume levels of the zones based on their loudness, and automatically crops the zones. Choose the Optimized drop zone that works best for the samples you’re using:
With Zone Per File, Sampler analyzes the pitch and places the samples on the right keys. If you add samples of the same pitch with different velocities, Sampler creates velocity zones. Use this if you’re adding multiple samples of pitched instrument notes.
Other great info: