In EZ Player Pro (shipped with Superior), I load my drum midi file. From there, I can send the whole "kit" to Superior, or whatever sampler I want. OR...it recognizes each drum instrument. I can create two tracks/channels. Load Superior on one, Slate on the other. On the superior track, I create separate layers for each drum part I want (a layer for cymbals, a layer for snare, etc.). Drag the drum part I want to each layer. Select the map/wrapper to Superior. Then on the Slate track, create layers again for the drum parts I want in Slate (toms, kick, etc.). Drag the drum part I want to each layer. Then select the map/wrapper for Slate. (this is all within the EZ Player interface)
Make sure you have both Superior and Slate loaded up in your VSTi rack and everything routed correctly. The PDF with EZ Player does an okay job explaining this, and there are several youtube tutorials out there. They all explain it better and in more detail then me. I'm just giving you the "gist" of it. But by doing this, EZ Player is splitting the midi file parts for me and sending them to the appropriate sampler. No more need to duplicate the midi track and selectively turn on only the drums I want. Life got a lot easier for me with this tool! (once I got my head around it, that is)