Board Thread:Plants vs. Zombies 2/@comment-27580764-20160113211621

Why do all the world since Dark Ages (Except Neon Mixtape Tour) include 5 free plants and 2 premiums/gemiums or 2 gemiums and a premium? Even Far Futur brought a few more plants. Sure, you can argue that Dark Ages has only 20 levels, and that is a plant every 4 levels, but the other worlds have 32 levels (with Frostbite Caves being the odd one with 30 levels for some reason) and still, include only 5-6 plants while worlds like the Wild West include 7 plants although they are 25 days long? 