Hi Thomas - Thanks for laying out your thoughts. Let me clarify my math and you tell me if you still see a disconnect.
First, the calculations are based on 30 days of labor per month. Why don't we assume days off, you ask? Several reasons:
1. The 6-day workweek was a Christian invention; Romans worked 9 days out of 10, and slaves and laborers worked every day. 2. Dividing construction by 30 makes for much cleaner math for the common unskilled laborer (3gp per month / 30 = 1sp/day)
3. Assuming daily work avoids the problem of calculating overtime. Put another way, if laborers work 25 days out of 30, but slaves work 30 days out of 30, does that mean slaves have a lower daily construction rate? Or does that mean you get more work out of slaves? Can you get more work out of laborers if you have them work 30 days per month? How long can that crunch be sustained?
So, with that in mind, the system in DAW yields the following:
Unskilled laborers produce 3gp per month, so dividing that by 30 yields a very clean 1sp per day.
Apprentice craftsmen produce 10gp per month, or 15gp per month when supervised. That yields 33cp per day, or 5sp per day when supervised (33 x 1.5 = 49.5, rounded to 50cp = 5sp)
Journeymen craftsmen produce 20gp per month, or 30gp when supervised. That yields 66cp per day, or 1gp per day when supervised. (66cp x 1.5 = 99cp, rounded to 1gp)
Master craftsmen produce 40gp per month, or 30gp when supervising. That yields 1gp 33cp per day, or 1gp per day when supervising. (40gp, less 25%; 40 x 25% = 10; 40-10=30)
1 Master, 2 Journeymen, and 4 Apprentices yields 1gp + 2x1gp + 4x5sp = 1+2+2 = 5gp per day.
Does that track?
"A maximum of 12,000 workers may work on any given construction site. The first 3,000 workers on a construction site work at their full construction rate. Any additional workers thereafter work at only 33% the normal construction rate, although the workers’ wage rates remain the same. Thus a project built with a work force of more than 3,000 workers will end up costing more (in gp of wages paid) than the labor cost of the project. However, the project will get built faster."
1st 3000 workers x 1sp per day = 300gp
2nd 3000 workers x 1sp per day x 33% = 100gp
Total construction rate = 400gp / day
Construction price is 120,000gp
With 3,000 workers: 120,000gp / 300gp per day = 400 days
With 6,000 workers: 120,000gp / 400gp per day = 300 days
Construction time reduced by 25% (400 x .25 = 100; 400 - 100 = 300)
With 3,000 workers: 300gp per day x 400 days = 120,000gp
With 6,000 workers: 600gp per day x 300 days = 180,000gp
Construction cost increased by 50% (120,000 x .5 = 60,000; 120,000 + 60,000 = 180,000)
So as far as I can tell everything lines up. Where are we disconnecting?