If your snare note does a Tom hit in slate, you're doing something wrong. They all have their own maps for the extra articulations or sounds but the basic midi notes from the general midi convention should be respected.
Use 36 for kick, 38/40 snare, 42 closed hat, 46 open hat, 41/43/45/47/48 for toms (48 maybe isn't allocated since most banks don't have 5 toms), 51 for ride, 49/57 for crash, 52 for china
If I'm right these are the most used notes. Then you can tweak by experimenting with the specific mapping of your drum software.