Jaeimseu
3rd Black Belt
Something jumped out at me there... Your senior grades are on the left?
We line up for example like this:
Master
1d 1d 2d 3d
4k 3k 2k 1k
9k 9k 9k 8k
So if someone lined up to the right of someone else (facing forwards) they would be more senior.
Is this how everyone else lines up?
This is how we did it back in the USA. I can't speak for other dojang in Korea, but at ours we line up by belt color (black in front) but we don't bother with what Dan rank someone is. The subject of what Dan someone is basically never comes up.
In our "beginner" classes, the highest beginner rank lines up at the front and higher ranks line up behind them, because they are "visiting" the class.