Necro charming - conga line vs clump

[Philistine]

Good morning everyone,

After studying up on the zone, I've been soloing in Howling Stones on my necro for about one level now. I'm sure no one will be surprised to learn that videos from Sessedrix and Rektyu have been very helpful in getting a good idea of what to expect and strategies for the area.

After charming for a level though (ie, I've got some experience but am still figuring it out) I'm not sure I understand the benefit of the "conga line" method of fighting groups of enemies, opposed to just rooting them all in a clump and letting stuff burn down your pet really fast then moving onto the next one.

I'm sure I'm just being a slow study, but what is the advantage to the conga line method, please?

Thank you!