>>36349877There's definitely others, but I tried to ignore comparisons that are just things like "these are both dogs/bakus/etc." and canon ones such as Seviper/Zangoose or Basculin/Basculin. Also included ones that are aren't really similar, just commonly associated with each other in fanon.
So in order from just friendly duos to downright death battles:
>Machamp / Conkeldurr>Furret / Linoone>Sandslash / Excadrill>Scyther / Lurantis>Clefable / Gengar>Lucario / Zoroark>Gardevoir / Gothitelle>Milotic / (pick from Gyarados, Serperior and Primarina)>Tsareena / Lilligant>Charizard / Dragonite>Typhlosion / Feraligatr>Hydreigon / Sylveon>Incineroar / Decidueye>burasutofeel free to add more or disagree with any