I'm not really sure if this is a bug or a suggestion. It's kind of in the middle ground.
For...complicated reasons relating to promotion and relegation that aren't really relevant to this post, the league I'm a part of (league number 36) partially migrated to a new league and then the teams that had done so (including me) came back. These teams now have numbers that run in the 30s and 40s, with a lot of numbers in the single digits and teens vacant. We assume what has happened is that the game assigned those numbers to the teams that left, and then when the new teams arrived, even though they were the same teams, the game just gave them the next "available" numbers.
The result is a bit silly, though. I can see three solutions: shift all the numbers down to occupy the lowest available set of numbers (giving somebody 0 rather than 1 if the previous champion isn't around, maybe), make the numbers editable by the league admin, or make the game remember position in the league's previous season, and therefore which numbers a team is "entitled" to.
And yeah, this thread might be a bit motivated by me having "32" rather than "1" on my car, but it's also useful for at a glance memorisation of who's who, and it feels a bit silly not to have most of the low numbers on the circuit.