I do agree with the concept, that all starters should have a 2nd type by their final evolution. They're the pokemon you have the longest in any game, and I really like seeing thme change they're dynamic more than just their look. A torchic into a blazekin is a good example, just like tepig into emboar. The fighting element adds a need to deal with flying and psychic. While in the other hand you have cyndaquil into typhlosion, who doesn't not change at all, remaining as a good special attacker with fire. The evolutions don't create a need to have more typed with you.