Paradigm Surround Help

I have Monitor 9 v5 fronts, CC-290 v6 and I couldn't pass up getting the titans v5's so I relegated them to rears. I set them up and wasn't overly enthused. I know they are originally meant for mains, but what gives? I had to swap them out with my rears that I had because they weren't matching. Any suggestions? Or will I just have to find a place that sounds best and play with my adjustments? Any ideas on how far or close to walls, how they could be angled or and if a solid surface or stands would help? Thanks in advance since I'm new to speaker placement and getting the home theatre rolling.