A city can be assessed by the number of transactions that take place in it and the type of transactions. Collectively the individual members of the city have generally shared aspirations. .
Each congregation is made up of individuals, depending on the mix in the congregations you get more or less genuine Christians - as you do anywhere or in any denomination.
Jesus said this
(Matthew 18:20) . . .For where there are two or three gathered together in my name, there I am in their midst.”
I joined a lovely congregation but over time it changed. The sister congregation was not recognisable as Christian.
Jesus had God's Holy Spirit and he is the head of the Christian congregation. He never gave it to the Watchtower. Those in union with Jesus are individuals not corporate (which means body) entities. The body is Jesus Christ.