It's certain that relic doesn't design the 3vs3+ to be balanced as the the 1vs1 & 2vs2 modes. Just check how they design maps. Almost every new map we got for 1vs1 was designed with a balance background in mind. They are mirrored, open to allow flanking and all recent balances adjustments have been made for 1vs1 & 2vs2 maps.
Now check the 3vs3+ maps for example. Lazur Factory has been a bottle neck galore since release and the new map lorch assault has 5 Vps!!! And a huge fucking castle just for eye candy with no tactical depth what so ever. The only maps that seem to be balanced are steppes & general mud.
Sorry for a bit of offtopic, but that with steppes and general mud balanced...really got me