GAC, 2.5 mil difference against opponent

I don't think that skill-based matchmaking is working in an environment where "size" or "weight" does matter. Nobody would tell an olympic boxing champion in lightweight, "hey, you are sooo good, you can now fight others in super heavyweight class!" ;-)
And there are a lot more sports competitions which have weight-based classes before skill comes into. Even in professional esports you don't have to battle others with a huge material advantage so why setting the level that high in a simple mobile game?