I think I've already made a thread about this, but I can't find it, so again, I'm in need of help with stacking units.
http://doodle77.dyndns.org/tutorials.php?id=227
Currently, I'm following this tutorial, but when the DT's get disabled, they don't move, they just keep spinning, and spinning. What I'm trying to achieve is this.
http://www.maplantis.org/index.php?map=795
I've looked at the triggers, but they are discombobulating me. Can anyone explain this to me?

Try looking at this map instead. It might be easier for you to figure out. All it does is stack Marines.
http://www.maplantis.org/index.php?map=1256

The way I learned is by stacking sprites. Enable/Disable/Enable and then move them. They have to be preplaced sprites in the map.