FMA is close to truth
Truth is only if your arrows in the display show in the direction u want em' to show and the airplane is pointing in the direction u want it
It's called basic flying
E.g airbus heading
FMA says heading still the dam thing is turning in de wrong direction
engine display and PFD is the real truth
Uber-pedantry wins the day again.
Point is pushing buttons is only half the battle. Need to look and see it actually did what you asked. Not much time to try and recall what was or wasn't written in some manual.