Advance Scout has a
special ability that is manually activated, and isn't even comparable in this situation as has been pointed out.
Glimpse of Fate is more comparable, but it too has a
triggered action that has an explicit
trigger (noted by the use of one of the phrases "When", "Each Time", or "While") activated by losing initiative, and so it's more similar to
Advance Scout than it is to
Harrowdale. In both of these cases, the card has an
action with an
effect that continues to live on if and when the card has left play, until the action's text says so.
Harrowdale is different: it has no explicit action associated with its "until the regroup phase" game text. I searched for a card that is like it and found nothing. I even wrote a script that pulled up every single card that had the phrase "until the regroup" in it, and
there wasn't a single card in the entire game that's worded like
Harrowdale is. (I can provide the list if anyone's interested).
To reiterate: every single card that has an effect that lasts until the regroup phase (usually giving/preventing fierce, defender+1, or strength bonuses) is either the effect of a
special ability (i.e. a bold phase action such as
Skirmish:.) or an automatic
triggered action (i.e. has the phrase "When", "Each Time", or "While"),
except Harrowdale.
In addition, I can't think of any card that produces an action trigger that lives on longer than the card itself does (this is not the same as an effect outliving a card; this happens constantly as is entirely the basis of Events).
All this supports the argument that it was meant to be worded "Each minion skirmishing a
![Rohan [Rohan]](https://lotrtcgdb.com/forums/Smileys/classic/rohan.png)
companion loses fierce and cannot gain fierce until the regroup phase.", but was not due to oversight.
All that being said, I do think that the current operating behavior in gemp is
technically accurate, but this is as established a unique case that is ripe for errata.