I did note something clever. Most final evolution starter concepts end in a triad of key themes on every gen: Brains/Coolness, Brawns and Beauty. There are exceptions like 1st gen (both 3 were monster themed) and 6th gen, with 6th gen basing on RPG roles (some say Skyrim Constelations as a pun). So as far as I've seen, here's my idea of the starter concept themes placed on each final starter:
1st Gen - Venusaur (Monster); Charizard (Monster); Blastoise (Monster)
2nd Gen - Meganium (Beauty); Typhlosion (Coolness); Feraligatr (Brawns)
3rd Gen - Sceptile (Beauty); Blaziken (Coolness); Swampert (Brawns)
4th Gen - Torterra (Brawns); Infernape (Coolness); Empoleon (Beauty)
5th Gen - Serperior (Beauty); Emboar (Brawns); Samurott (Coolness)
6th Gen - Chesnaught (Warrior); Delphox (Mage); Greninja (Thief)
7th Gen (rumor/leak) - Rowlett's Evo (Brains), Litten's Evo (Brawns), Popplio's Evo (bronybait Beauty)
1st Gen - Venusaur (Monster); Charizard (Monster); Blastoise (Monster)
2nd Gen - Meganium (Beauty); Typhlosion (Coolness); Feraligatr (Brawns)
3rd Gen - Sceptile (Beauty); Blaziken (Coolness); Swampert (Brawns)
4th Gen - Torterra (Brawns); Infernape (Coolness); Empoleon (Beauty)
5th Gen - Serperior (Beauty); Emboar (Brawns); Samurott (Coolness)
6th Gen - Chesnaught (Warrior); Delphox (Mage); Greninja (Thief)
7th Gen (rumor/leak) - Rowlett's Evo (Brains), Litten's Evo (Brawns), Popplio's Evo (