How?
LE
Well, apart from the two songs sharing the same topic,
The Living End resembles both
Back on the Dancefloor (musically, but also, again in terms of topic) AND
So Far from the Clyde (totally different topic, but sharing a melodic line). I could imagine that they excluded it from the album for that reason - too close to previous songs. Whereas
Ahead of the Game, while typical Mark, is more its own song, if that makes any sense.