Thank you, Nicolas, for helping the fool here building his exceptional case.
Yup, it's as you say: brands in single dropdown... of course. And I hear you regarding nameboxes - again, haha... 
Obviously, I'm anything but a script pro, but can't it be made with a
if(.....category_type == 'manufacturer') {
$query............a.category_name ASC';
}else{
$query............a.category_ordering ASC';
}
or so? Guess I'm kidding, lol. If it were possible, you had done so already.
But then nothing to worry, I'm good with the order statuses being "the wrong way" now... a small price to pay.
On a side note, I apologise for not having noticed it being you in the other thread, too. Just so used to seeing Jerome here as the lonesome HM warrior!
Thanks again.