But the whole idea of the game is that it is a BOARD GAME first and foremost, miniature game second. When you buy the base game you are getting a full game that can be played as is. All the other boxes are just meant to be expansions to said game (because again board game first, miniature game second). It's the same thing for an Arkham Horror, Descent, or any other game with a bunch of expansions. You buy a base game and expansions to give you and your gaming group more options.
The reason the wife and I bought everything was because it's a fun game, with a miniature wargame feel, that is easy to teach and fast to play. With my wife and I buying everything none of our friends have to buy in and we all get to enjoy the game in some fashion. If you are trying to turn Puppet Wars into a tournament ready, build some super list that is perfectly optimized you are doing it wrong and missed the focus of the game.