Iam wondering the same. Also I normally get in the top 10 with all tournaments I have been in but for the Arena one iam in now it totally bonkers.

I have 130 points so far. Think not that bad and will get some more points. But iam in spot 47! the top 10 starts with 450 points and the number one has 950!!!! how? Iam struggeling to get by in Bronze IV. Dont tell my those guys are also struggeling in bronze IV. They more seem like Gold players with easy wins. You dont get 950 points when you are in Bronze. Why am I in the same group as those players :S

Only level 53 and 45days. 0 legendaries so far (but iam getting Brogni). Their matchmaking is weird.

Points required per milestone reward are determined by your level - I know that there is a difference between people at level 50 or below, and those above level 50. Not sure if there are additional categories, like maybe for players below level 30 or so it's even less? 

As for grouping, it's normally based on how well you performed in previous tournaments - so @Gondorath if you're normally top 10 in tournaments, it makes sense that you would be put in increasingly harder groups. 

Ive read that somewhere as well indeed. Well good way of stripping away the fun and competiveness when you are place with people probably playing way longer and spending way more just because you perform well. Only been playing 45 days....And now they want to put me in vs gold tier players while iam in bronze..... gg

Because if you are doing well they think that you are likely to spend more money to keep up with people in higher tiers, never forget everything they do is about money

Ah that explains it. I think I leveled from 49 to 51 since I last tried for a tournament lol and partner is around 39