We're investigating the reported flickering issues with The Division can Crimson 16.3. Please try using Crimson 16.1 to see if this resolves the flickering.
Please install Crimson 16.8.3.
I had Flicker and the negative Crossfire Scaling Issue on my system i74770K, GPU1 = Sapphire HD7970 OC 6GB, GPU2 = Sapphire R9 280x OC 3GB.
Note my cards are not on the Crossfire Compatibility chart.
For me negative scaling is fixed since Crimson 16.8.1.
I get FPS improvement of 1.42 in the Division on Ultra and can run at 56-60FPS at 1080p.
Hope this helps.