I'm not a fan of divisions, because i don't get a good picture how i'm placed withing the league. How many divisions there are per league? Is A division actually better than B division or are they just named differently?
Doesn't feel transparent enough.
The game creates as many Divisions (of, let's say, 100 players) as it needs to fill the 'quota' for each of the Leagues (Iron, Bronze, Silver, Gold, Onyx) from the playerbase of those who have competed in a given season.
So let's say, for simplicity's sake, 10,000 people qualifty for ranking over the course of a season, and 20% of the population are shunted into each League (maybe the top 2% enter a 'Grandmaster' League, reducing the Onyx count to 18%). There are thus 2,000 people in Iron, Bronze, Silver, and Gold at any one time, 1,800 in Onyx, and 200 in the Grandmaster League.
People can move in and out of Leagues depending on their performance, but within a League, the game creates 'Divisions' of 100 players that are intended to be representative of the League as a whole. So if I am 17th in, e.g., 'Iron 7', it is telling me that I am (roughly) in the 83rd percentile for the Iron League as a whole. The game creates and populates these divisions as needed, and moves players sideways from Division to Division to maintain that (rough) sense of placement relative to the greater League. This tells me, at a glance, how am I (roughly, in so far as is possible) doing, and gives me an immediate set of peers to compete with and compare myself against -- or to challenge, if that feature were implemented, allowing me to make aggressive upward advances. This also serves to personalize the experience, so my opponents are not a faceless mass (Arena is characterized by a feeling of uncertainty about how you're doing, with the outcomes often entirely incongruous to how you felt you were doing; this can't be 'solved', as such, but it can be improved), but other players like me that I can put a name and skillset to. And then every so often the game pits me against players from a higher or lower League, just to check I'm more or less where I should be: the consequences of winning to players from a higher League (or losing to players from a lower one) ensure these games are for higher stakes than the inter-Divisional ones.