Carrying lots of sacks

I’m still struggling a little bit with one roll per turn in practice, when it comes to simultaneous independent action.

E.g. I was reading the factors for Laborer last night, and they include how many sacks are being carried in each hand. If, once loot has been doled out, you have 3 PCs all carrying a large sack in one hand, how is this done through a single roll?

I assume this must be something like highest factor based on the PC carrying the most, add 1 for every PC who is also burdened and then roll singly? This would mean all the helpers get the same Condition, if applicable, and so mechanics fit the narrative well enough.

Helpers never get the same condition as the character making the test. They get lesser conditions.

If everyone is carrying a full large sack in one hand, each character makes a Laborer test. The Grind continues to wear them down—everyone’s going to get hungry or tired really fast.