The Dance with Dragons expansion for the Game of Thrones Board game includes a Walder Frey combat card, whose text reads:
Any player (other than your opponent) who grants support to your opponent must grant that support to you instead.
When playing with the Mother of Dragons vassal rules, could this card be used to affect your opponent's vassal that is supporting them in the combat?
For example, say the Arryn player enters combat with the Stark/Bolton player, and Baratheon, who is a vassal of house Arryn, has a support order in an adjacent zone. If Stark/Bolton plays Walder Frey, do they receive Baratheon's support instead of Arryn?