BlakMajiK

I'm not 100% certain, but I think only the distance to the target. But, having more range to the mob gives you more room to move around to get the good angle to flick the mobs into the corner. The mobs come out of wormhole with a knockback effect away from you, so you want to position yourself where that knockback will drive them into an obstacle to keep them bunched up. Many times you'll find yourself at a range where the "line" through you and the mobs to the corner is not dead on, and what can happen is the mobs fire out and slide down the wall and aren't as grouped up as you'd like. More range means that's less likely to happen, as you'll have more leeway in placing YOURSELF. Hopefully that makes sense.

Consider six slotting wormhole and placing a range IO. Keep in mind there's a period of time between the activation of wormhole and the actual teleport where the mobs will aggro, the more distance between you and them the better. Also, more range means an easier time in placing the exit, so you can knock them into a corner.