Perfectly stated by death. Although each of my troopers does handle Basic training slightly different the basics always stay the same.
To obtain a pass in basic training and be eligible for a promotions ST's are to:
Pass 2 out of the 3 Faces exercises.
Show an understanding of climb swep basics by reaching the top of a wall.
Show understanding of each and every formation. (ST's are given multiple chances to reach the correct formation and must get each formation correct at least once.)
And finally show understanding of basic firing commands and sequences.
The last of which is where you are having your issue. This section is run differently by each of my troopers and no two do it the exact same. The trainer in question was my WOI [ST-06] Hideyoshi, who does not have a mic. Hideyoshi has conducted many trainings and the issue of not having a mic has never caused the training to run any longer than it should. Hideyoshi employs a different method when he tests firing commands by giving you a command that is not first obvious to everyone. The command you stated was that of Unload on purple. There is no purple square however the back plate is a purple material. As such most do not fire on anything. should you first fail Hideyoshi ALWAYS explains what the command means and how he entends you to execute it.
I myself do not see any reason that members of our community who do not own or want to use a mic are excluded from assisting those that are new to the server. Should there be anything that you disagree with or any comments you wish to make feel free to pass them on to me either IN-Game or on Discord (Madfm#6789)