*sigh*

The point is that we've seen plenty of actions showing the FS are doing things off screen throughout the series ... you are making blanket assumptions that Slayer is the ONLY DO minion who does this kind of work...

Here's a quote from before LOC where Graendal is openly talking about killing others of the Chosen!

The Fires of Heaven
The First Sparks Fall

"Nearly half the surviving Chosen in one place. And no one trying to kill anyone. Who would have expected it before the Great Lord of the Dark returns? Ishamael did manage to keep us from one another's throats for a time, but this…"

And she's clearly talked about Asmo as a traitor too

The Fires of Heaven
The First Sparks Fall

"He can see where it took Ishamael. And that is the point. A point Graendal raised. Once we were thirteen, immortal. Now four are dead, and one has betrayed us.

And she's obviously not just a kidnapper...

The Fires of Heaven
The First Sparks Fall

Graendal's face contorted, and Rahvin prepared to shield himself against whatever the two women might hurl at one another, prepared to Travel at even a whiff of balefire.

Show me where Slayer is prior to Asmo's death.. in the friggin Two Rivers trying to kill Fain, he's not a part of Rand's storyline at all until much later!