Ubbe, go onto SWGOH.gg
across the top bar are white letters with a drop down menu. Select GAC and go to Scan Player. Enter your Ally Code and then sync your account. Under your name and guild name is another menu / profile / collection / GAC / Etc... Click on GAC
This will show you your total wins for the 3v3 season and the 5v5 season. If it's close to 50 percent wins, GAC is working as intended. For the last 7 season total, I have 32 wins and 28 loses. WOI
I have faced hard opponents and I use google search "counter to (toons name) SWGOH (3v3 or 5v5)" and beaten accounts with 3 mil more GP than me. I have also lost to accounts who are very focused and more disciplined than me with far less GP than me. This is a resource management game. Watch some videos by Bit Dynasty, Beaver, Scrybe Gaming and Ahnald101. Focus your efforts on one team at a time and don't be distracted by the new shiners.
Harvest and Darjelo have nothing to gain by giving you bad info. We're only here trying to help you improve and understand the game better to improve you're strategy and abilities. You're kinda all over the place with no great teams to help you. Choose to open Galactic Legend Leia Organa and I can 95% guarantee you will be in a far better position.
There are two great posts I wish could be pinned discussing mods and mod strategy on the forums which all players should look at and follow. Mods, Zeta, Omega, and Omicrons matter. And learning what teams to put on Defense in GAC and TW will improve you tremendously.
Credit to Master Seedy:
Modding: Quality, Farming Efficiency & the Cull | EA Forums - 13162736