I'll try to explain how the matchmaking could be.
Imagine, you just start to play Supermechs. On level 1, you need to collect 3 stars to level up to 2. You gain a star by winning a match and you lose 1 when you lost a match [...] and you can play only vs your own level.
You won several times and are now on lvl 3. That means you need to win 5 matches in a row to become lvl 4, but when you lose a match you will go back to lvl 2.
That eliminates all multi issues, as multis can't play (often) against each other. One will always level up, while the other always will level down, so they can't play.
The weak players will be on the lower levels, while the good ones will be on higher levels and face other good players.
Its a very simple system.
This does not seem to be the same as Liran is suggesting. Atleast not what I understood... I agree with j^8 that it is too easy to stay at your rank. Gaining 1 star for a victory and losing a whole rank when you lose seems like a smart idea, so if you win 1 and lose 1 you'll stay at lower ranks. If you win about 4 per 1 loss, you're more likely to be pretty much stable at a higher rank. With a rank system like this, you would need many more battles to get up to the top rank, so cheating would be very hard. With the proposed system of 1 win, 1 lost you can easily fight 1 match between each match dumped.
If the proposed system is implented, 20 ranks are fine (although I don't think it will work too well). I'd rather have more penalty per loss and fewer ranks.
And if you are ANYTHING else than 30, you will have HUGE problems with this new ELO system, as matchmaking will only be determined of your rank, not mech level (as I understood). This will most likely upset many players who used their time getting lower level items, and is left with nothing good for higher levels. They are forced to play a new style, new level or even start over with a new account. This could result in quite a few players leaving the game... If I also understood this right, you're now going to win a medal out of numbers of matches won, no points? So you gain nothing extra from defeating a player with many wins that week, compared to a "regular" player.
Pretty much this would result in the player spending most time winning the medal, not neccessarily the most skilled player. A world champion in my eyes is not the one who played 100 hours that week, but the one who gained the most for his battles fought, as the current ladderpoint system proves. Of course, more time gives more points overall, but you have a chance if you never lose to compete with the players who can play more hours than you.
Personally I think that you should still be able to play lower levels. If matchmaking was exactly like it is now, just a third side added to it, and you are only matched with a mech +-5 levels of your mech, and +-(X) of your rank it could work fine. This way you will face more competitive players at each level, and still be able to play lower levels mechs. I also think there should be an extra reward in defeating a player with many wins, in a row or whatever, like the current system has.
Of course these are my personal thoughts, I don't say they are perfect. But if you are interested in improving the gameplay to be more competitive and meeting players as experienced as you are, for a challenge and not a boring fight, I'd say the proposed system should be taken deeper look into.