Been trying to find a thread from around the time of the RTW demo time that went into this subject but can't get it yet.

The command interface did change slightly (and for the worse) between STW/MTW and RTW. There's Berserk_Yas' point about the inability to do a few of the more complex (but useful) things that STW/MTW allowed, like control an entire group's move and the facing they have both during and after the move.

DVX BELLORVM, in STW/MTW, alt-RightMouse caused the group to face to the spot you clicked on. That isn't the case in RTW/M2TW (IIRC, it moves to that spot and reforms with it's current facing).

Another one that I really miss: you select a group and drag it out, keeping the left mouse button down. Now clicks on the right mouse button caused it to toggle between redrawing with frontages relative to the original unit numbers/size and redrawing with depth constant but frontages adjusted to the current unit size. So handy late in battles when some units much reduced in numbers.