for maghda, i notice it's different to some groups.
what we did was to split into 2groups. 1tank will aggro Maghda and stay in 1corner. she's basically stuck there once she has her target on the same place.
3full dps will camp at the other corner, jsut wait SK will teleport himself to one of you randomly, dps like crazy. so most of the time SK will stay with the 3dpsers without the interference of Maghda's painful swarm+arcane. and if SK do teleport to the tank, WAIT there. dont rush to SK. SK will definitely teleport back to the other group. it was a quick n clean run.

* to add on, the good of this is you dont really get summoned skeletons scattered all over the place adding burden to the tank that's on Maghda. running all over in between swarms and arcanes are too risky.
and also notice maghda does not summon a lot of arcane if she only has 1target instead of 4targets around her.