Is it better to spend coins on card collections or on villages?

In my own opinion and experience, save it for the villages. Some sources will say "build twice around the village, then purchase chests." I did that, and my villages still got decimated and I had to spend extra to repair them. Every chest you earn has cards in them, and, let's face it, CM hands out some serious chests!! Never hard to get cards. Build your villages all at once. They get expensive to repair and build, also you don't have to worry about using up your shield or keeping the rhino fed.