It's a bit confusing and clunky right now :
- Characters that are in a different state (hiding or not) dont follow you, at least those that are hiding dont follow characters that arent.
- You have to split you group by dragging portraits off other characters (you see a chain, pull it until it broke), it creates separate parties.
- Drag over characters to regroup them together.
There need to be an autofollow switch, in addition to formations, like in other BG titles (and a drag rectangle to select characters too).