Sanderson said that Demandred's identity is the biggest mystery in the series and that it would pay off in the end.

Demandred launching a mediocre army from a mediocre nation against the Light will hardly be impressive.

The nations infiltrated by all the other Forsaken generals - Be'lal, Sammael, Rah'vin and even Semirhage were all more powerful than Murandy. It does not make sense that the most accomplished and most arrogant Forsaken general of all would take Murandy as his base of power.

50 000 Murandians will mean very little compared to 20 million Trollocs, the combined Seanchan armies that Semirhage was trying to control or the Dark Ashaman under Taim.

I still believe that the Shadow will have need of a powerful, organised and channeling capable military force to truly threaten the Light in the Last Battle.

The Seanchan would have been the perfect tool in this regard, and their strictly authoritarian society even made for a plausible scenario under which they could have served the Shadow. I think RJ missed a beat by letting the Shadow lose the Seanchan.

In my view, Demandred HAS to bring something of similar strength to the table. Shara or an army of mad channelers from the Isle of the Madmen would still be my most optmistic answer.

But failing those two, the Black Tower will have to do.

Murandy? Inconsequential in the bigger scheme of things.