Pad tracks are not used for every kind of song. Randomized silence will also play a role.
Customization in the DAW is expected, keep what you want and delete the rest.
Maybe I did not really get what "pad" meants for you in this context. For me "pad" is associated with the soundcategory "pad". So long notes, often part of chords or chords, which build the background and emotion of a song but of course follow the chordprogression ? So what does "pad" if clicked mean and do in mugen ?