I have an idea to make the Iroquois a bit better. Make the Longhouse a Unique Improvement, instead of a Herbalist UB. This fixes the persistent issue of camps.
Longhouse
Unique Improvement. Only the Iroquois may build it. Can build in Forests or Jungles, or in Non-Desert or Snow tiles that border a Forest or Jungle. Longhouse tiles are treated as Forests as long as the Improvement is unpillaged. (Can't use Longhouses, to build more longhouses further away). Can be built-in or adjacent to Iroquois Territory.
This improves the spottiness of their UA because they can use the Longhouses to extend and connect forests and jungles for road and movement purposes. While also slowing the movement of enemy troops because Longhouses count as forests, so you can block off territory. As well as improve forests early in the game, before others unlock Lumber mills. But not introduce a full-on forest growing mechanic.
As for the yields, I'm thinking that it would benefit from the same extra yields that Lumbermills get from tech and policies. Maybe also a single production on the tech that ordinarily unlocks Lumbermills. In addition to the base yields of
+1 Food, +1 Production, +1 Culture. +1 Gold if bordering a Camp or Plantation
However I'm not super attached to these yields, and so they could be changed.
But the basic improvement before tech buffs would be
3 Food, 2 Production 1 Culture (Grassland Forest)
3 Food, 2 Production 1 Culture (Jungles)
2 Food, 3 Production, 1 Culture (Plains Forest)
2 Food, 2 Production, 1 Culture (Tundra Forest)
3 Food, 1 Production, 1 Culture (Grasslands)
2 Food, 2 Production, 1 Culture (Plains)
2 Food, 1 Production, 1 Culture (Tundra)
With the 1 Gold bonus being fairly common for neighbouring a Camp or Plantation. And on gaining a normal Herbalist, all these tiles also get 0.5 Food (since Longhouses count as Forests) So the Iroquois can get a lot out of the basic Herbalist, even if it isn't their UB anymore.
It could also be swapped around, so that the Gold is in the base yield, while the Culture comes from the bordering of camps and Plantations. Not really fussed either way.