The skills improve incrementally, and pops occur when an unrelated sublevel is high enough to pop with a 10% or less increase. Sublevels impact salary and performance, so pops aren't very impactful beyond being cosmetic indicators of progress. There's not much randomness there to me?
I'm trying to read this to understand what you're saying. Basically, after reading it about 10 times, this is what I think you're saying: all of the skills besides the skill that you're training get the 10%. You only see pops in the skills that have a high sub-level. So really, nothing random at all is happening.
Interesting theory. But that's all it is, a theory. And if true, then the news posting is misleading in my opinion.
But if your theory is not true, or I am misunderstanding you, and the skills that get the 10% change are chosen based on a coin flip, then I'm sorry. That's random. If you like, I can be more precise and say it is a random process or random function.
FYI: saying sub-levels have little impact (I assume that's what not very impactful means) is either false or misleading also. For sure they have an in-game impact.
Run of the Mill Canadian Manager