Bingowings said:Even so the fighters are attacking both the capital ships and trying to stop the Rebels entering the superstructure.
Besides the focus is on Luke, Palpatine and Vader so having a bunch of fighters inexplicably wandering around may prove to be a bit of a distraction at that point in the film.
i agree, it may had to the enviorment, but it would be distracting. besides, the emperor thinks the sheild is still up at that time. he'd prolly get distracted as well.