Not necessarily. Kharos seems much more interested in Rowan than the Twins. He send his priest to you, not to them and he sends you prophetic dreams. Rowan can also be much more loyal to Kharos' ideology than the Twins ever will be since their evil is opportunistic and with little thought behind it; Rowan can develop into a character whose evil is calculated. If this is Act 1 up to the fall of Rastedel, then I can definitely see in Act 3 for Rowan to place Bloodmeen and possibly the Twins themselves under his control with the direct blessing of Kharos.Sounds like something that'd happen at the very end of this game, no? Defeats the premise.
So you could definitely have an entire act where Rowan redefines his relationship with the Twins before the final act