I was under the impression that the Super T was the one that was combat proven and owned all over the world and that the AT-6 was a prototype.
"the Super Tucano “has logged over 100,000 flight hours, 16,000 of which have been in combat without a loss.” Seven countries are using 173 Super Tucanos around the world today."
while the AT-6 while used has been only a training aircraft with no combat.
anyway ... up the the powers that be in washington on this one ...