Let's see if I can help explain why people's dates are all over the place.
I created a fake scenario below (so don't get all excited about how the classes are slotted because I totally made it up.)
You'll see at the top portion are lists by facility of those who have their TOL (sorted by time/date of TOL receipt) and are awaiting class dates. For enroute I slotted 5 slots for 3 facilities in each enroute class (which is fairly accurate) and then for Tower/Tracon I randomly put in some facilities and slots available.
If you look at each group of people that are color coded, they will fall into the slots in the grid below of the same color (for those of you who are colorblind or are on a monochrome monitor, I've added arrows). You'll notice that people don't go in order of who get's their TOL first amongst the entire group, but by facility assignment.
Those people Orange Italics did not get slotted for this round of classes and will need to continue to wait for an available class while the list of those waiting will continue to grow.
I hope this makes some sort of sense to you.