Encourage stance dancing;
Bring more diversity into gameplay.
Step one:
Eagle Eye (

Spiral-Fletched Arrow (

Step two:
Special effects for each stance:
Scout stance - On Hit 25% chance to apply an Enchantment that will increase damage for 10% of all Path of The Skirmisher abilities for 10 seconds;
Assault stance - On Hit 25% chance to apply an Enchantment that will increase damage for 10% of all Path of The Skirmisher abilities for 10 seconds;
Skirmish stance - On Hit 25% chance to apple an Enchantment that will increase damage for 10% of all Path of The Scout abilities for 10 seconds.
Conclusion
It should encourage stance dancing since main damage abilities will be tied to certain stances and help both Skirmish and Scout stances which currently underperform.
There is also a simple counter play - shatter the enchantment.