I really like this idea! I miss having a few herds around and it's a tidy and neat way to add them without creating "extra" lands. I would assume challenging and stealing would still be the same too.
Active
Obscene || Fyr || Ciri
Semi-Active
Link || Bardot || Vindictive || Stendarr
On Pause
Ledger|| No Crosses Count || Joplin || Gryffen
Ledger|| No Crosses Count || Joplin || Gryffen