Enemy target circle improvement

There are skills that some jobs have that depend on hitting the back and the sides of the target. Sometimes I think I got its back, but it actually wasn't (like with ninja's trick attack). and other times like with ravanna the boss spins around on its own, rapidly switching which side is which.

We have an arrow that shows the front of the enemy, but its harder to tell where the flank area ends and back begins. So having those separated by color or a pattern would be helpful (like sides dashed and back with a single line rather than a double one, for example).

Also some enemies like Leviathan's tail don't have positional requirements, so having circles look different for those would help. Right now they simply don't have a frontal arrow, but that isn't easily noticeable.

For the target ring, see image below. Hope it's help :)
source: not sure, I take it from google.
http://i.imgur.com/HVP2IBW.jpg