An -11 AC component is basically Shadow Vortex which was the aggro spell of choice for SKs once Disease Cloud got gutted. It doesn't have the recourse effect, but buffing is minimal aggro anyways. It's not unreasonable to assume the ATK debuff component will be more aggro than buff recourse anyhow.
I can dig on The Wayback Machine if really needed, but AC debuffs are very good aggro up until PoP (?). And even then, Vanazir was still pretty ok for tanks.
http://thecrossroadstavern8833.yuku....5805/SK-advice
The numbers might not mirror live, but even if you use your numbers for shadow vortex and add the DD portion, it's going to still be solid threat.