Part of Ongoing Effect
If you play Smokestacks of Gnaak and then I play another Smokestacks of Gnaak nearby, the game tries to apply both lose-ability effects in layer 5. Since your Smokestacks are older, the game starts with that effect. Your Smokestacks causes my Smokestacks to lose its ability. Then, when my Smokestacks ability would be applied, it already lost its ability due to the first Smokestacks. Therefore, the first Smokestacks 'wins.'