Simple or unsubtle forms or Compulsion clearly have existed for a long time ... Liandrin is a perfect example, she's clearly effected by what was done to her, but it took a while for the effects to be clear. The Liandrin we see toward the end of the series is a totally different person from the early books. Even before she was broken by Suroth, the weave itself broke her by making her only concern "LIVE" ... despite what must have been a dibilitating need to Channel.

However ... more complex/subtle forms have always been shown to take time. Graendal and Ishamael are the only people we've seen use this form. Moghedien and Rahvin used blunt force which backfired on both of them. Certainly all of the Forsaken are aware that there are more "refined" methods, but that by no means says they are capable of doing it. Much like Graendal and Moghedien could talk about Healing weaves they could not themselves perform.

Aran'gar's compelling of Ramshalan is in no way shown to be "subtle" .... she merely tossed a weave on him ... we actually know more of Delana's weave which Nynaeve could see. With no time to see what possible differences in Ramshalan there is no evidence that Aran'gar managed a subtle compullsion on short notice.