Everyone needs to stop seeing patterns in everything. The applications are roughly done in order of arrival but obviously they can't make it perfect. There is thousands of applicants and probably several hundred IRCC employees dealing with cit applications.
If they were trying to enforce a strict first in first our policy they would probably have to employ scores of people just taking care of this. Which means yay everything would be perfectly in order of arrival but the average processing time would go up because less staff can do the ACTUAL job.
Looking at all spreadsheets, IRCC keeps them roughly in order. Obsessing over a number of weeks is pointless.
In short: chill, please.