As-is, lumbermills are a specific point production improvement that bring you health, being otherwise equal to mines. I'm not suggesting a radical change to this because 1. this mod is not primarily about radical changes and 2. not everything in the game has to be equally useful, because a lot of folk still play for fun.
A minor change to a better direction still matters to us who do use lumbermills even now.
Edit: Well, due to Windsor's somewhat biased analysis I'm actually motivated to throw my number analysis here as well:
Lumbermill: 2
1
½
Watermill: 2
1
Workshop: 1
1
(1
2
with Caste)
I ignored commerce because I don't consider this stuff for my cottage cities. Extra points if you can figure out what the numbers mean / if the numbers look familiar.
A minor change to a better direction still matters to us who do use lumbermills even now.
Edit: Well, due to Windsor's somewhat biased analysis I'm actually motivated to throw my number analysis here as well:
Lumbermill: 2
1
½
Watermill: 2
1
Workshop: 1
1
(1
2
with Caste)I ignored commerce because I don't consider this stuff for my cottage cities. Extra points if you can figure out what the numbers mean / if the numbers look familiar.

in all cities.
. I don't find too much use for slavery - perhaps that's the difference in playstyles. The map type also matters. I probably wouldn't chop a tundra forest for example.