I do not know how matach making works in TT, and I do not know how match making works in TT Tournament Groups.

But I do know that you can be matched with players in other tiers in Classic Arena.  It's been very clear recently since the addition of G5.  At reset I have exactly 2900 points and the first 3 opponents on my list had exactly 2600 points, meaning they were in G3.  I know that doesn't answer your question but it's all I have.

Thx for response, but your rank in classic tournament can change immediately when you reach different some peaks (2000 / 2300 / 2600 / 2900 / 3500, etc... ) so if some tournaments is ongoing, players who start tournament lets say in G3 could be on hour later in G5 or G1 - depends on his actual points.

But in tag team arena - rank can change only in Monday i think. And from this point, you face to people only in your rank.

This tournament start on Wednesday, so every rank for every person is clear and also points for win is also clear. So i dont understand how is possible that somebody has significantly strong oponents then others (are in different ranks and same group in tournament). I know if I win I have an advantage for win more points than somebody with lower rank, but when points in tournaments are higher, you face much more stronger opponents and its not equal. 

I think it should be in TT tournaments only facing people with same rank, otherwise is not fair (points for wins / different base of strenght of opponents)

I'm constantly being paired with teams that have insane speed and all the strongest epic void legos. This is stupid, I'm only in silver 4. This content sucks

U have the advantage getting more points as you stated. Plus the difference between b1 and b2 can't be that much.  Winning the tournament usually will be the one who buys more refills with gems. They are very cheap. 15 gems a day would provide u 50% more battles.