The question of whether or not gameplay-binding-dream is as powerful as fluff-binding-dream aside, I personally, very much doubt that Soulblighter possessed it. The Binding Dream is an inhibition, controlling the actions of those will a willpower significantly less than the caster. What I believe Soulblighter was using was a geas: these Brigands are basically hired mercenaries, and, as such, the Brigand Leader will have some kind of contract, saying something to the effect of "I [insert name here] and my men promise to serve and obey Baron Kildaer (and his boss, Soulblighter) for the fee of x gold imperials per month (this part in invisible ink) for ever and ever and ever! And when we die, the Baron's boss, Soulblighter will be perfectly within his liberties to raise us all as Thrall and get us to fight again without pay.(end of invisible ink section) Signed (in blood) [insert name here]."
This agreement having been made, it is then possible for Soulblighter to enchant the Brigands to do exactly what he wants (a liberal interpretation of the word "obey"), much in the same way as Balor may have enchanted the Myrmidons to do his bidding.
