This is a nice idea, but it might be necessary to be able to define the formation and order when characters are being linked. I have a specific formation which I use for general exploration, so I would normally want the characters to form a specific arrangement when I link them. Perhaps a combination of "hover the mouse pointer over a character picture" then use the up/down arrow keys to change order might work together with a Baldur's Gate style formation selection display? This may start to clutter up the screen though.
I agree, the game is looking very impressive now and is a lot of fun to play.
