Ok, I just got off work and am thinking:
put Maur, chainmail and heavy arms in the boat with Xander and the npcs who live in the village, and if there is enough then add the two prisoners. the rest of us take the under earth passage, hustle or maybe even force march to catch up.
The boat would need to be pulled by the druid/shark
Keep any locals who are still armed and armored and full of fight with the main group in the passage.
So, Caerth and Maur together with Meridith, Timmins, and Wieland. Xander goes with Maur. That makes sense. Maur wouldn't want the duergar out of his sight. Wieland won't want to let Aries or Eike out of his sight, so the launch will likely be burdened with a heavy load.
So, no faster than 4 miles/hour as a base speed. With two rowers, I'm willing to increase that to 5 miles/hour. Maur would be one rower and either Xander or Aries would be the best choice for the other rower. Eike won't row unless forced and the three NPC allies will be more concerned about watching the three prisoners. Aries would be willing to row more than Xander.
Angus, Quinn, and Phar hustle through the underground passage with Cruel Justice lighting the way. Aureus will insist on going with Phar and the group will likely need her eyes and skills as a rogue. Brutus will go where Quinn leads.
However, with his breastplate, Quinn only moves at 20 feet, so that would be 4 miles/hour if the group hustles. Quinn could choose to ride on Angus and while that would slow Angus down a bit but with his
horseshoes of speed, he could still move along with Aureus, Brutus, and Phar at 6 miles per hour based on 30 feet movement. Rules for Hustle:
"A character can hustle for 1 hour without a problem. Hustling for a second hour in between sleep cycles deals 1 point of nonlethal damage, and each additional hour deals twice the damage taken during the previous hour of hustling. A character who takes any nonlethal damage from hustling becomes fatigued.
A fatigued character can’t run or charge and takes a penalty of –2 to Strength and Dexterity. Eliminating the nonlethal damage also eliminates the fatigue."
this will
A. reduce the total in the boat
B. place the slower and high risk persons in the boat
C. keep from encumbering those in the passage.
D. if any high risk persons want to escape, there is a convenient shark to remind them not to try and get away in the water.
C. Quinn could go on the boat but that would leave those traveling through the passage shorthanded if they run into Tarrak and his horde. I assume the goal is to either ambush the cultists underground or go around them to get to Carnell first. There wouldn't be any light for Phar, who has low-light vision not darkvision, without Cruel Justice lighting the way.
Timmins is wearing light armor (leather kilt), so he could take Quinn's place underground and carry a torch. No one would have to ride on Angus that way. Timmins is the most experienced of the NPCs, but his AC isn't very high (only 15), and he's past his prime (52 years old). If he gets into a fight with deadly foes, he likely won't survive.
