KahlessNestor
Adventurer
I'm pretty sure one caster can't Guidance everybody for the same task. You've got a ton of NPCs too, don't forget. They could go hide in the Quarry until the all-clear. Obviously, the elves should do fine sneaking. Speaking of Drui, we seem to be missing Archon again.
Maybe we should send Drui and a few of the Elves to guard the Commoners in the Quarry? Or even to take them back to Daggerford.
If Archon comes back, we can say that Drui got them safe enough and then turned around to come back. Maybe take two elves with you, leave the rest with the Commoners. (It's up to you if you want whassisface the Stonelayer to come along, or if "There's the bridge! I'm outta here!" is enough for you.)
Have you checked out the "official" Warforged rules yet in Wayfinder's Guide to Eberron? After a long rest, they can choose what armor to be wearing. So you could downgrade from heavy to medium.