Yes you can use crossfader to select and change slice number on each track indeed.
I usually use 1 or 2 tracks for drums, but if you use 8 tracks, it can be annoying.
Another solution is to use midi loopback, set all tracks on the same midi channel, and use CC17 to control all tracks.
Control All for OT! Plockable.
Tested, works like a charm.