from WH chapter 22:

"Kill him," the M'Hael had ordered before sending them to Cairhien, but he had been as displeased that they were found out as that they had failed. Far Madding was to be their last chance; he had made that as plain as polished brass. Dashiva had simply vanished. Kisman did not know whether he had run or the M'Hael had killed him, and he did not care.

"Kill him," Demandred had commanded later, but he had added that it would be better they died than let themselves be discovered again. By anyone, even the M'Hael, as if he did not know of Taim's order.

And later still, Moridin had said, "Kill him if you must, but above all, bring everything in his possession to me. That will redeem your previous transgressions." The man said he was one of the Chosen, and no one was mad enough to make that claim unless it was true, yet he seemed to think al'Thor's belongings more important than his death, the killing incidental and not really necessary.

Those two were the only Chosen Kisman had met, but they made his head hurt. They were worse than Cairhienin. He suspected that what they left unsaid could kill a man quicker than a signed order from a High Lord. Well, once Torval and Gedwyn arrived, they could work out—


So, we have direct evidence that Demandred was indeed giving orders to Asha'man, and by him saying to not get caught again, shows that he had given them orders before this. It also appears that Kisman thought Taim was getting his orders from Demandred, (probably because he is a well known Forsaken), and, Kisman is obviously dumbfounded that Demandred doesn't know about Taim's same order to kill Rand.

It's also clear that Kisman had never met Moridin before this event, (nor did he know he was a Forsaken), so he also wouldn't know that Moridin was Nae'blis, and therefore preeminent of all the Chosen.

I agree Taim is most likely under Moridin's thumb, but it does make you wonder why Demandred was ordering around Kisman, Rochaid, Torval and Gedwyn, who, by all accounts, were some of Taim's top cronies.