I would agree with most of what
Groin and
Durelin said on the subject of following Balin, these "military leaders", and probably Balin's closest friends. Obviously, it will be also easier to get the events out there rolling just with the smaller number of Dwarves, there may be also need to send somebody to call upon reinforcements when it shows up that there is more Orcs than what is good for them etc., etc.... whatever the Mods also may have planned, for that matter.
And as for hurrying up, I am of course not pushing anybody to hurry hurry finish their character
(I am actually surprised that the bios have been done so fast). Better to take your time and make your character the way you know you are really going to like him and know you would like to unfold his personality in this direction you set...