Goldnight Commander and Thatcher Revolt
All three of your Thatchers will get +3/+3.  They do enter the battlefield simultaneously, and in the process of Thatcher Revolt resolving, Goldnight Commander will trigger three separate times.  By the time you reach the point of going to resolve each of the three Goldnight Commander triggers on the stack, Thatcher Revolt has long since finished resolving, and all your Thatchers are present on the battlefield, queueing up for their Giant Growths!