The criteria for all those that apply is the same.
Some of the early better applicants came to SLE and their files were opened earlier. After that, all files are looked at for a standardized threshold in order to open. If you meet the criteria, your file is opened.
DoDMERB scheduling depends more on your level of file completion - at least as far as West Point is concerned. Candidates may have been scheduled by other academies for the same exam. When West Point is ready, they will request the results of that exam.
So, yes, faster means better chances in that the earlier your file opens, the sooner you can complete it, the sooner your DoDMERB is scheduled, the sooner you have to work and resolve any issues that arise so you can be 3Q.