Once you hit level 15 now, you will be matched against anyone from level 15-30. You will be matched against players that are the same rank as you, or a rank above or below you. (so if you are ran 7 you will be ranked with ranks 6-7-8). As you play you will find yourself in a comfortable rank eventually where you win/loss ratio is 50%. Until you ind that though you will win a lot or loss a lot.

Is there no way to make the matches a little bit fairer?

I'm rank 3 and now i got 6 matches in a row vs rank 1-mechs with tons of mythical items!

The best I can is take half of their hp before I explode...

6 matches vs much better equipped opponents, 6 times no chance, 6 losses in a row and still forced to battle such mechs?

It does try to match you against people with the same rank as you, maybe one over if you're only a couple stars away from that level, but if it can't find any matches at that level, it will expand the search. IT is there so you wont' sit there for ever waiting for a match.

I really hope you're exagerating when you're saying 8 times, if not, there is a serious problem with the system (well, might be anyway).

I do think part of the problem is that some people focus more on the single player than others, which means their mech improves, but their rank does not. And so they start off with a level 10+ mech against level 4 mechs, which creates unfair battles. I've suggested a "fix" for this, we'll see if others find it to be a good one.