Church size does not happen by accident. Rather, size is determined by structure. It is possible to stratify a list of churches according to size based on a description of their structure, both logistical and liturgical. Certain kinds of structure simply cannot support a church larger than a certain size. On the other hand, other kinds of structure scale very rapidly and are limited only by the population density of the region adn the efficient use of facilities.
This is important because it requires some intentionality in regards to church size when you choose the structure of your church. You may have other reasons for choosing a certain kind of structure, but when that structure inevitably results in a certain size congregation, you cannot claim ignorance.
I could describe for you the structures of churches of various sizes, but instead I want to ask if a church should deliberately choose to be small.
Does God want little churches?