Battle group UI is smart
I've not played any RTS games with a Battle Group kind of setup, but when I finally figured out these two things below, I was smiling ear to ear. How clever!
1. Why, when I select a tier 2 unit, does the unit building UI show up? That seemed like a bug, until I realized (sadly after an hour) that you are asking a factory to fill up battle group slots with the requested units! When the units come out, they are already part of the battle group, and act accordingly. That's genius!
2. If you have a rogue squad of tier 1 units, right click on a tier 2 unit, and it will become part of its battle group and act accordingly. Love it!
Sorry if this is such common knowledge that I seem like a noob. But I am really floored by this.