Huoh - GP is nothing and thankfully that was removed from the calculations.
Yes, its a problem for newer players that we have large player base and some that had been active before drop down and are "out of their league" roster wise.
But they have equal right to climb and go for Carb3 too. As long as everyone is in the same ladder you will face opponents that are ranked like you. They might not be same power but their rank is same.
I mean it wouldnt be right to pair non GLs vs each other and lot GLs vs each other -> then GL owners would complain that players without GLs climb as they get free ride.
Pairing is not meant to be fair - it is meant to be of your position. And its meant that every division has about 20% of players. So Carb has 20% and each Carb4 has 4% roughly. That 4% players around same ladder rank - not GL rank.
There are no solution so that it works for everyone.