Lots of things and grammatical categories form rather reasonably indexed sequences, and for some of these, there's also a sort of 'obvious' starting point, i.e.
1: default – big2: comparative – bigger3: superlative – biggest
We can compare some other things where the indexing doesn't necessarily seem very much like the natural numbers, but rather like the integers:
-1: yesterday0: today1: tomorrow
Similarly, tenses could be considered as mapping to negative and positive numbers. A system that combines aspects and tenses could reasonably be seen as mapping to some subset of the rationals (-1.5, -1, 0, 0.5, 1, 1.5 or whatever you fancy, where '.5' is perfect or whatever. Coming up with a reasonably interpretation for that series is left as an exercise for the reader!).
Now, this isn't really a way of categorizing or describing or classifying or anything along those lines - saying that 'comparative is two' or 'today is zero' does not really inform us about anything at all.
What would be interesting, though, is derived forms that reuse morphology from one category, say the natural numbers onto something where the number metaphor suggests a mix of negative and positive numbers. Say
1 → -1: "day": yesterday2 → 0: "day-er": today3 → 1: "day-est": tomorrow
I have not come up with any more interesting examples than this – that'll basically end up a challenge for the reader. I imagine such twists could be interesting though.