One Type Thing vs Many Types

@josh @emmanuel

May I ask if, in terms of performance (e.g. search for), if makes positive sense to have many different types of things instead of just one?

In my app I organised everything using a single type, I assign codes, for example I could have a type called counties and a type called cities, then have a parent field in cities referencing a country. Instead I now have one type called elements and for countries I have elements with code 1 and for cities I have elements with code 2.

Would my app perform better if I have different types rathe than just one?

Thank you in advance.