The issue in the current meta of SoD PvP is that All tanks are dealing high damage with impossible counters vs Melee. Casters can steal do a lot of damage like Boomies, but their burst damage is not as it was in the previous phase.
In short, you want to fix the Cries to Shamans, which is an extension to all tanks: Have BGs reduce avoidance by 50%.
Problem is now solved vs tanks, but now your dps goes form a flat 5% avoidance to 2.5%. May not mean a lot to you, but someone will complain about it.
You cannot please everyone, but this is basically the easiest fix in the history of fixes.