>>36909493Some of these themes aren't the themes at all.
Gen 2's theme is tradition. The Gen 2 starters are all pure-typed throughout their life, which is what a traditional Grass-, Fire-, or Water-type Pokemon would be like. All 3 families also have stats that are derived from or exactly the same as the Kanto starter families across all 3 stages. (i.e. Croconaw and Wartortle have the same exact number base stats, but they are assigned to different stats. Cyndaquil family and Charmander family have exact same base stat numbers in every stat.) There is also the grass "dinosaur" (yeah, I know Venusaur is technically a toad or whatever, but the theme sticks) that develops a flower as it evolves. The water bipedal reptile with a cream-colored mouth and body. And the fire starter that has fire spouting out of its body with a cream-colored body.
Gen 3 is nature. All 3 starters are located in a different biome in Hoenn's ecosystem. Sceptile's family resides in Hoenn's lush jungles, with Sceptile's Japanese name, Juptile, possibly being a combination of jungle and reptile. Blaziken and co. reside in Hoenn's volcanoes. And Swampert and co. reside in Hoenn's muddy swamps.
Gen V's theme is melting pot. Each of the starter families is based on a different culture that all came together in Unova (USA). Serperior is derived from attire from French nobility, Emboar is based on a specific character in a Chinese myth, and Samurott are obviously derived from Japanese samurai.
Gen VII's theme is JRPG 2.0. Decidueye is the archer. Primarina is the singer that provides buffs to the teams. And Incineroar is the grappler character that takes damage and inflicts more back at the opponent. Also, it could be occupation-based as well.