Why you think that? On each lvl up your pokemon receives some points to base statistics. On lvl up Charmander receives another points than Charmeleon. Conlusion? In example #1 you have Pokemon with 98 levels stats as Charmander, 1 level as Charmeleon and 1 as Charizard. In example #2 u have Pokemon with 16 levels stats as Charmander, 20 levels as Charmeleon and 64 levels as Charizard.