Pescaroca, Papelrana, Pajajera

This is a special trio:
 
Pescaroca (Lumineon+Solrock): This rock shaped fish can live on land just as well as in the water. It has spikes on its rear that defend it against attackers. It is good against Pajajera but weak against Papelrana.
 
Papelrana (Ariados+Tangela): Papelrana lives best on the ground, or jumping from tree banch to tree branch. It is very fast and its arms are remarkably strong. It is strong against Pescaroca but weak against Pajajera.
 
Pajajera (Skarmory+Pidgey): Pajajera's wings are so sharp they can cut trough trees during flight. It is the most mysterious of the tree as it is cleary too heavy for flight and its wings too thin, yet it soars over the clouds. It is good against Papelrana but weak against Pescaroca.
 
Anyone notice anything about the three?