That's actually an extremely great point. Good character progression is important to get you more invested in a story. I definitely don't like overly stupid characters either.
This is one of those games I only bother checking for updates once year. I'm actually surprised it updated in March. Time to play chapter 6. See you lads next December.
There are too many characters but the game has made it fairly clear who the main cast is, the family (though the family is still growing). Even Tanya gets mentioned a lot but not shown. Having a lot of side characters is just to not let scenes get stale with the same people repeatedly.