I like the measures to make the game balanced and fair also to players with low level cards, and that there are ways for us to get more packs without having to buy them, such as the league rewards and the newly-introduced daily quests (which were a pleasant surprise to me)!
And now we have these adjustments. I like them! (though I admit I'm guilty of using the Alric + Medusa + Mermaid combo :P ) I've had a lot of trouble facing teams with the Zintar + Undead Priest (Weaken) combo, and higher levels. The levels being automatically adjusted in the leagues sounds like an interesting way to balance things out. Just yesterday I lost to the same person twice in a row whose cards were all max level, while my highest level card was a level 3 Common card.
Speaking of twice in a row, I've always thought it's strange whenever I get matched against the same person twice in a row. If we decide to battle with the same teams right away after our battle ended and get matched against each other again, the result will most likely be the same (unless one of us gets very lucky and some randomly decided factor like hits and misses completely changes the tide of battle), so just by checking our opponent we are practically sure whether we're going to win or lose. It takes some of the fun away, I think...