I don't think you can make an "equally good" case for Demandred, for a few reasons.

The seeds of Masema's fanatism were planted at Falme. He became obsessed with Rand in a near religious way over the next months, while Rand was hiding in the mountains, while the Shadow was hunting for him on the Plain. He already had dreams then. The big question is whether Masema had a true epiphany, going from hating Rand completely one minute (and thinking him Aiel) to becoming one of his most ardent admirers after he saw him over Falme.... It may well be Lanfear, who was around and observing things, found Masema's hatred dangerous and tampered with him, sending him visions (she would not have killed someone in Rand's inner circle, the risk it backfired was way too high, considering her plans).

Most of the Forsaken got released only after the second seal broke, dixit RJ. The winter after Falme is damn early for Demandred to already have found Rand and hatched plans to corrupt his allies. Locating Rand was easy for two Forsaken with the ability to find his dreams, to locate him in the Pattern thanks to his ta'veren: Lanfear and Ishamael. Graendal singled out the ability of those two in a Forsaken meeting, and no one challenged her statement. Ishamael rather clearly sent the attack in the mountains. Lanfear was clearly the one who sent dreams of Callandor to Rand to attract him to Tear (it was never Be'lal, who told Rand at the hand of his surprise that Rand came for Callandor so early. He didn't think he would be so foolish to attempt that move, thus... he's not the one who lost time trying to bait him... It was Lanfear all along, who wanted Rand to move for Callandor now, before the other were too strongly established. She saw what happened in the Pattern when the three ta'veren were together, with their close allies. She encouraged Perrin to go on, Mat to leave Tar Valon, she plotted to have the girls go to Tear, and arranged things so the BA would know immediately, messages would be sent to await them so they'd get captured and end up right in Be'lal's lair (Be'lal who also remarked to Rand he didn't think these girls would be of any use... it seems to be Mesaana who got ideas to capture Rand using the girls as bait, and suggested to Be'lal to have the BA capture the girls. As I said, Be'lal wasn't expecting Rand to come)

Perrin and Mat rushing to meet with Rand, Moiraine too, the three girls already in place, captured... that's an attempt to reproduce the conditions met in Falme, where events turned spectacularly in Rand's favour. Sammael tried to intercept Rand and Perrin when they entered his territory. Rhavin was super pissed about Elayne, thinking Be'lal was planning something against him. Be'lal must have claimed he had nothing to do with any of this. The three men were barking at each other in TAR, and Ishamael tried to calm things down.

It's Ishamael who tried to stop Lanfear's attempt with Grey Men. In the Tower to kill the girls (Lanfear sent Slayer to stop those), in Tar Valon against Mat, in the South against Perrin and Rand both. In his desperation, Ishamael finally came himself, and died for it.

I don't think a plan for Masema to build Rand an army of religious fanatics who believe him divine is much Demandred's style. The man has no humour. Unlike the BT, this army would be Rand's in truth too... It's a crackpot idea to begin with, far more in the crackpot style of the delusional Lanfear who tought soon Rand would be in love with her and in her control, or Ishamael who likes to have the Light fight the Light, but we know Ishamael was not in the mood for any of this at the time, so... Lanfear was also the one who was quite happy for Rand to be surrounded by allies, and who feared Rand might be killed by the Forsaken.

What Sammael spoke of as events that had Demandred's touch all over them isn't Masema turning into a Prophet. Sammael was almost certainly mistaken, he threw all the Dragonsworn/Child of the Light problems into one bag and labelled it "Demandred". It looked terribly like a proxy war, because Sammael must have figured out there was no connection between those "Dragonsworn" and Rand. The thing is, this almost certainly had nothing to do with Demandred. Masema was a real madman, and the one using the war in Ghealdan as one excuse to gather all the forces of the CoL was simply enough Pedron Niall. And we know it all started by accident, when the border tension turned into war because Galad seized a boat Masema intended to seize to give Nynaneve.... That's how the war between the Prophet forces and Amadicia began... there's no mystery there.

Niall was also the one who was waging a campaign using other Masema's men like fake Dragonsworn proxies, having Carridin control bands (infiltrated by the Hand of the Light) attacking people from Altara to Tear, in the hope of justifying an intervention by the Children of the Light. The fact this was starting to spread to Illian is why Sammael was getting furious. He made three related moves: he passed a warning to Demandred via Graendal, then he found the trace of the man who seemed to be the proxy (Carridin) behind it and took control of him, and finally he spitefully spread Rand's enemies the Shaido in the whole area, spreading chaos and likely to attract Rand's attention to these parts sooner than later. If Demandred had interests there, let Rand come deal with this and root him out - that was Sammael's plan. All this for nothing... Demandred had nothing to do with it, it's actually Semirhage with the Return who was moving for this territory eventually - and of that Sammael had no idea.

I don't think if Demandred had Masema as a proxy, he would have waited this long to move against Perrin. He would have done so right in Ghealdan.

It rather appears Masema was "on his own" since Lanfear's death if not before. He needed no pushing to do what he did, after a bit of early guidance via Dreams.

The sole involvement with the Shadow Masema seemed to have in the later game is via Suroth, and there's a fair chance she was pushing not the Shadow's agenda but the Corenne's. Suroth must have heard of Masema's anti-AS beliefs. She was probably making a deal with him to have Masema deliver Ghealdan to the Seanchan without a fight. Then Masema vanished via gateways to an unknown location, and Tuon arrived, putting a wrench in whatever deal Suroth and Masema had made.

The same comment made about Moghedien can be made about Demanded too. The whole thing is way too theatrical and over the top for Demandred. He's a dour bureaucrat turned military strategist, no tel'aran'rhiod drama queen. I hardly think appearing as divine visions of Rand in madmen's minds is the sort of things Demandred is in the habit of doing...

I think we'll find out that Demandred's plans are very down-to-earth and methodical, with a few important gambles.

I'm fairly convinced he has stood on the side and built himself a secret army, starting to plan how he would destroy or better any new achievement of Rand as he progressed. He's ridiculed the other Chosen and their powerbases, called them fools to take an alias and try to take control of a nation... Obviously, himself didn't do that...

He's got a plan to retake all Rand's conquests, and gain back the powerbases the other Chosen have lost for the Shadow. I think Demandred's biggest gamble will turn out to have sent Taim to Rand instead of bringing him to his own secret powerbase. When Rand put Taim in charge, that opened the great opportunity to recruit men for Demandred's army openly. All male DF could thus be tested, and most of those testing positive would be told to hide the result and remain behind until someone else came for them. Only very few men would go to the BT with Taim's recruiters, enough for Taim to build a faction that wouldn't attract too much attention, and that would eventually take the place over for the Shadow as TG begin. The bulk of the dreadlords were most likely trained elsewhere, probably somewhere in the far Blight.

It seems to me Demandred has chosen Caemlyn as his main headquarters to direct the Last Battle, while Moridin insisted to keep charge of the North. As soon as the battle rages in Caemlyn, the dreamspike effect will be extended to cover the City (Perrin said the effect in Ghealdan stretched for many leagues), to prevent or at least delay the LIght's channellers from coming to the rescue, and trap those foolish enough to have entered the Dreamspike zone. And that's merely Demandred's opening gambit, IMO. I think he will move for at least Cairhien and Tear at the same time. He needs a lot of access to Waygates and Portal Stones. With Tear, Cairhien and Caemlyn, he'd have a nice network, with fortified cities to park massive armies of Shadowspawn.. and the means to send them elsewhere.