Hey Weakl1ngs, just use the mountain rowdy more
I can see where you are coming from, since Pure Frost has a hard time against Pure Nature and Nightguard with CC. Overall I don't think that nightguard is too strong and it is kinda neccessary against other units. Stone Tempest, Mountaineer or Reaver would make certain Matchups really hard and oppressive. You can already see that in other Factions that don't use Nightguard. Once it got implemented the use of L-Unit + Buffs/CC's/Heal really went down after a time when Instant T2 Reaver/Vile Blood/Deep One were one of the best and easiest strategies in the Game that got many people in the top 40 in a time when BF had a lot more players.
What I want to say is, that it is weird that it does not bind power but nerf with caution, because Nightguard is keeping the abuse of other L-Units in check. And I'd rather keep the Nightguard how it is and not risk this old cheesy Tactics coming back.
I think that IF you wanted to nerf her, it should be a decrease in range, this would maily impact Frostsplashes, since they have more time to coldsnap or Pure Frost can use War Eagle scream. When the Nightguard got nerfed a long time ago, when it was even used to counter EP's, there was also a big discussion about the powerbinding aspect. Someone from the dev Team can correct me but I think it is not that easy or better not worth it to implement a powerbonf to enemy units.