you dont understand word flexible. if there are 20 players per side in queue, MM will make 2 matches with 1st match with players with lower BR weapons and second with higher BR weapons. this is relative and not absolute. you dont get static ±1 BR or ±2 BR. you get number of queues that is proportional to number of players. to paraphrase devs : “high BR player can end up in low BR match and low BR player can end up in high BR match. this should be rare occurrence.”
that is why overall you dont need to know number of BR brackets and player distribution by BR brackets. and like i showed you before there are enough players to fill multiple queues without a problem, so worst case scenario shouldnt happen or will rarely be happening (by that i mean BR 1 vs BR 10).
i will try to say it again, THIS is the exact thing i try to improve, to UNIFY the playerbase IN LESS queues:
instead of those 3 fronts, just make a general axis vs allies. BR will spread out the players enough imho.
so you want japanese to fight with germans against soviets and USA in moscow? that is stupid. why not go fully ahistorical and have anyone vs anyone.
like i said currently there are enough players for multiple fronts (only weak link is japan, but we will see how it will go post merge)