[@The Harbinger of Ferocity]
The unarmoured caster is lingering ten feet beyond the front of the two non-casters, so by your current action you would be attacking one of the non casters. If this is okay, the attack will indeed hit and slay the target. Otherwise you would have to gain more movement speed, mainly by Dashing, which would forgo your attack. I am assuming you will take the attack instead of the second option here.

Anyhow, next up [@Norschtalen] with [@Gordian Nought] right after.