Alright, poking around, and I think I want my biomes to be a bit more diverse options-wise than what you did; question on if you think I've gone overboard:
Class 1:
Plains
Hills
Mountains
Class 2:
Savannah
Grasslands
Steppes
Class 3:
Rainforests
Cloud forests
Temperate forests
Taiga
Class 3:
Wetlands
Mangroves
Class 4:
Deserts
Scrublands
Class 5:
Tundra
Glaciers
Class 6:
Coral reefs
Atolls
Current idea is that players would have a mix of player-chosen and randomly selected biomes, but they wouldn't have access to more than one per class, and overall would be capped at between 3-5 classes (still a work-in-progress, so I haven't solidly selected a number). Biomes could still be combined (within reason), and it's a max of two per turn (and they cannot be connected to each other, I think).
Your thoughts on this?