Lots of people have commented on this idea... some way to do a partial select or deselect.
I made some comments about a "partial deselect" in this thread, back in June:
So.. I wouldn't call it a bug, BTW, but I do agree that I naturally wanted to "break off" units, and I did try several things before I found the disband option. Point is, though, if you want to interface to feel natural, maybe add a hotkey for partial disband and regroup?
So like highlight a bunch of units, hit a single key, and the units are removed from the group and regrouped together.
Would feel more natural.
Would probably also require a way to selectively click troops that are already groups (ex. alt. click to add/subtract single unit, ctrl alt click for all units of one type, etc)
The key problem that makes partial selection a challenge is their meta unit mechanic.
Once you group, it is like the application is treating the whole army as one big unit.
And therefore, when it comes to issuing commands, the issue isn't just about deselection... also need to consider removal from the meta unit.
Agree that the interface is problematic until they fix this.
I'm sure it will get there.