Two engine go around 101: Use one hand to Push and hold the thrust levers 3/4 of the way forward and use the other hand to pull and hold a pitch of 15 degrees.
Doesn't matter if it's a 747, A320, 737, 787, DHC8 or a 757 it works in all of them regardless of what modes/automation is engaged.
This didn't happen because of lack of training on aircraft type. This happened because of a lack of basic flying ability & airmanship