Arena match making

Toxicshiva

I think I'm in 2099

Giuliameij

I don`t really get what you are trying to say. Both matchups seem fine. The first picture your team is just pretty low. Since I cannot see what your match number is I cannot tell for sure. But it might be you used your low time either to early after reaching your streak. Or too late into building up your streak.
The second picture I a normal Thanos team which you are most likely to get with r4 champs starting from match 12 or 13.