The players in the balance team invest their time, even though knowing they don't have to, into making a better game for everyone including you. I think a bit of respect would be in order here.
Dose relic even appreciate the effort of the community testers? On several occasions balance patches were released with some seriously glaring balance issues (most recent example Katyusha buff, soviet mine squad wipe before that)). Several testers pointed out that their input was never considered, or that the changes were never made available for them to test in the first place!
I think relic mainly has community testers to play as many games as possible so they can have lots of data to use with their internal tools. Using this data they check units performance and statics and then draw their own conclusion.