Welcome! Glad to have you on board!
The term "rank and file" is used to indicate members of an organization, exclusive of it's leadership. I don't think it's a derogatory term. Some examples:
*** w94 8/15 p. 11 par. 2 This Good News Must Be Preached First ***
Perhaps some religious groups send some “missionaries” for a two-year stint into certain areas, but their rank-and-file members do not participate in any such ministry.
*** w92 12/1 p. 7 par. 1 The Blessing of Jehovah Makes Rich ***
In 1992 even the affluent West experienced a recession, and executives as well as rank-and-file workers found themselves out of work.
*** w86 9/1 p. 28 Must You Be in the Limelight? ***
Some individuals are used quite prominently, but others play rather inconspicuous roles as rank-and-file publishers of the Kingdom message.