The Great Commission is a matter of being sent! God sends preachers does he not (Rom. 10:14-15)?
Concerning your illustration. You have a mixture of people from various denominations divided over everything imaginable. In regard to the gospel some by beleive justification inclusive of works and others without works. In regard to baptism, some may be immersed, others sprinked and still others poured. They could no more be scripturally constituted into a Church as could the membes of a Masonic Lodge. However, even Masonic Lodges will not recognize any other Masonic Lodge that self-organized itself.
These mixed up variety of divisive professing Christians have no more authority to self-constitute as they would to self-baptize or self ordain.
The Great Commission was given to the body of disciples that habitually assembled with Christ as their "head" authorized leader from the baptism of John to his ascension (Acts 1:21-22).
The Great Commission was given to those who already "have" been taught to observe all things Christ commanded sharing a COMMON GOSPEL and a COMMON BAPTISM with a COMMON FAITH AND PRACTICE. It was not given to those identified as "them" in Matthew 28:19-20 or to those identied as "all nations" in Matthew 28:19 but rather to those identified as "ye" formerly identifed as "disciples" as only disciples can disciple others.
You are not Christ's disciple if you embrace ANOTHER GOSPEL than Christ preached (Jn. 3:16).
You are not Christ's disciple of you submit to ANOTHER BAPTISM than Christ administered (Jn. 4:1-2; Luk 7:29-30).
You are not Christ's disciple if you teach and observe ANOTHER FAITH AND ORDER than Christ commanded (1 Tim. 4:1).
A "disciple" is one who observes and believes what the Master teaches it is not one who is INVATIVE and goes making disciples by ANOTHER gospel, ANOTHER baptism and ANOTHER faith and order. Such an invoter is called a heretic not a disciple.
Good Biblicist....then you send some of the Apostles to NW New Jersey & plant the damn church.....Otherwise, I will!