One of the "problems" in pre-boarding is the way the various GA handle the situation. In NRT it seems very dis-organized....and in some areas, a GA is more forceful in expressing her/him self in such a manner as to aleviate some of the difficulties. If the GA "whispers" and simply walks around holding up a small cardboard sign...it seems to signal some rude people to "charge ahead"...I think their script should be uniform and stated more forcefully: i.e. "WE ARE NOW PREBOARDING THOSE IN NEED OF EXTRA ASSISTANCE - OTHER PASSENGERS ARE REMINDED TO AVOID BLOCKING THE GATE AREA....ETC. ETC. ETC." Some GA simply whisper the details and go through it so fast - I sometimes wonder what language they were speaking! The GA need a little refresher and some uniformity... (just my opinion and observations)