You may be right - it's possible that they have separate teams each dedicated to a specific task - checking application for completeness, another for possibly re-arranging the packages to a 'preferred review format', another for batching and sorting cases to go for review and (if they're digitizing them) then a digitization team before it goes into a feeder line to the case review officers.
As for predictions, my guess is that they're probably handling this by lots of a specific size (say, 100 cases per 'lot'), so it's possible (given the mountain of packages they're going through (and assuming there's nothing on the packages themselves to indicate the exact date they arrived at the facility (even though there is a separate record of it in the system that they're not cross referencing when sorting), it's possible that they (the sorters) have a rough idea of when a package arrived, but not the exact date, which would explain why a few slipped through the cracks and got processed along with the February bunch (and then returned for incompleteness as a result). It's either that or they've likely begun 'sorting' the March applications and doing the initial prepwork before the actual review process begins. So effectively, here's what I think is happening:
a) Applicant Sends Package
b) Package is Received at CPC
c) (Speculative Assumption) Packages are then grouped into 'lots' as they arrive.
d) Package is reviewed for completeness
e) (Speculative Assumption) Package contents are hand-arranged in specific order for digitization and review which varies depending on 'Single' or 'Family' applicant
f) (Speculative Assumption) Arranged Packages are then batched into new lots and are prepped for digitization
g) (Speculative Assumption) Applications are digitized
h) (Speculative Assumption) Applications go into feeder queue to be picked up case officers.
