I will let Nar go first, from his position, only 3 are in range, if he was closer, then he would hit the Halfling, and that would be bad.
Nar-Heru, you unleash your furry, engulfing two of the swarms and damaging another. The smell of burnt beetle fills the ghastly chamber. You feel the creeping effects of the poison (+5 damage).
(Lucian takes 6 damage from the fire).
Then an odd cold creeps into the room.
Forge even being next to the things, you also feel poison (8 dmg). You then begin your manic run…whether speech, motion, or smell, you do begin to bring the swarms to you. (not sure about moving through, but I see a path that seems to work). You are bitten many, many times on the way, (again, hit twice, 37 damage! And poison) invoking your shield which fries a few beetles and calling on the the armor of your ancestors. (heal 21 or 24?, down about 30 total). You then unleash your furry, with your great swinging axe strokes smashing many beetles.
Between Forges Axe and Nar’s fire, three of the swarms are below half their strength in numbers, but still quite deadly.