Chapter 2.1 - Heirloom of the Riddermark, started North Downs slayer deed while in Rohan?

[Hydranova]

So while fighting off the first two corrupted wargs that showed up as part of the quest, I got a "New Deed: Warg-Slayer". I either click the notice or open my deed log, and it's open to the North Downs page and shows I've killed 2/60 wargs.

Now, to be fair, I have both Warg-Slayer of the Eastemnet and Westemnet deeds in progress, both those are at 75 and 17 respectively.

Is this a glitch? I don't think I opened the deed log before since logging in. Or is there a larger story behind these wargs?

P.S.: I see what that Bard of Rohan was on about with skill swapping- the question is, how does he remember?

IMPORTANT EDIT: I forgot to mention this is Chapter 2.1 of the Black Book of Mordor