you gave a good answer !
in fact , there isn't a such thing in Bible named "God's earthly organisation" (even spirit directed)
God has "people" on earth today .... the fact that his people has to obey His commandments make him "distinct" people like old Israel Deut 4:1-9
from Jesus onward this people is composed by all "congregations" of Christ , so, no-organisation
in the Congregation God appointed no GB , but : 1Cor 12
28 And God hath set some in the church, first apostles, secondly prophets, thirdly teachers, then miracles, then gifts of healings, helps, governments, divers kinds of tongues.
29 Are all apostles? are all prophets? are all teachers? are all workers of miracles?
the wt "definition" for organisation somehow would fit with "God's Kingdom" , but the kingdom is only in Heaven now , not yet on earth !
the christians were taught by Jesus to pray for its coming on earth : only then , the "real" arrangement of God will be on earth !
until then, we live in expectation of its "coming"
1 Now we beseech you, brethren, touching the coming of our Lord Jesus Christ, and our gathering together unto him;
2 to the end that ye be not quickly shaken from your mind, nor yet be troubled, either by spirit, or by word, or by epistle as from us, as that the day of the Lord is just at hand;
3 let no man beguile you in any wise: for it will not be, except the falling away come first, and the man of sin be revealed, the son of perdition,
4 he that opposeth and exalteth himself against all that is called God or that is worshipped; so that he sitteth in the temple of God, setting himself forth as God.....