[quote=@Zombiedude101]
<Snipped quote by Ruby>

Would it be safe to assume they were at least involved in the riverlands campaign?
[/quote]

Not unless canon says they were involved. Maybe on a lesser level, like a few knights from the Vale just wanted to join in on the fight, afraid (correctly) their overly cautious Lords would hide behind the Bloody Gate. But not on a large force level, no.