I'm not entirely sure if I should post this here, but here it goes:
I'd like for Lukaer to be in group two, because he is a protective big brother and if he ran into Constans, Lukaer would not leave his side. Ever again. Look what happened last time he let him leave home. The thought was that Lukaer (and probably Mathieu) will set out from Lukaer's bannorn, heading east to Denerim, just in time to run into group two and, shock and suprise, find their little brother there. This isn't set in stone, of course, but there you have it.