I write all my groove templates into bottom of arrange page, on no output tracks. I save this as my song template.. I just drag the whole folder of grooves, onto a track, and in one step I've got 32 of the grooves from Linn Drum machine, and early Logic templates.. to make a groove, drag in the midi file, highlight, on the quantize window at bottom, there is a command called 'make groove template'.. their you make a groove template.. You could take the bass part of a different song, and groove your drums to it. You can use any midi file, one you make yourself.. etc..
at end.. save song, strip out all song parts, just leaving groove templates, and save as a new template..