Its a confusing process. I remember going to wharton and having a senior member of the admissions committee tell a group of about 50 of us that they printed the applications as they received them and that they would be reviewed in that order (during the review period). This, of course, seems to imply a linear process, where in theory, someone who submitted their app on the 8th should have received an "Application Complete for R 1" before someone who did it on the 9th.
But then again, who knows what they really do....
In case this helps, the ad com member said they dont check for SUPER STRICT adherence to the word limit for essays. She kind of laughed it off when a paranoid member of the crowd brought that question up. Obviously, take this comment with a grain of salt.