(Dates correct only if year of wages paid is 1999 and each of the 11 "hours" are 179 years).
There is no mention of complaints or murmuring against the third, sixth, or ninth hour workers. But while the "burning heat" of intense persecution claimed to have been suffered by JW apostates is expressed at length in their book 'Then is Finished the Mystery of God', the correct understanding of The Christ's illustration and the above diagram is as follows:
At any point in time during the Lord's symbolic "day" there are brothers who may have worked on earth in the "vineyard" of God for many more years and/or suffered greater persecution than their more recently gathered brothers. Any sense of superiority they may harbour over their brothers will be manifest in their failure to help cultivate their fellow Spirit anointed brothers for ministerial work in Christ's congregations. (Eph 4:11,12). There are in total 144,000 workers, with a number still on earth in the process of being cultivated and gathered to Jehovah at this time. (See 1 Cor 12:4-31).
But as for apostates who install themselves as "shepherds" in the spiritual "land" of God, Jehovah has said: "Here I am against the shepherds, and I shall certainly ask back My sheep from their hand and make them cease from feeding My sheep." (From Ezek 34:7-10). Jehovah is here referring to those called to be anointed ones but who corrupt themselves and in their apostasy refuse to shepherd His "sheep". (Luke 12:32) (John 10:16).