Think is this way: You are not an expert in pcs, you are just some guy who want to buy a good PC. You see X-model 5, and X-model 7, you will think "X-model 7 is newer and better".
There might be some internal logic is these names (or even gpu names which are also awful in this regard), but its not intuitive. I mean, even in this logic, 7 means 8 cores and 9, 12.
And even then its not easy to discern the generation.
Thise are just awfully confusing names. Naming it: Gen X, Y cores, Z hz, would be so much better.