Some plains village structure pieces never generate in Superflat worlds

The Bug

Certain parts of the village never generate in Superflat worlds, especially in the Classic Flat superflat world type.

Affected Structures

• minecraft:village/plains/houses/plains_small_house_8 (the building with three water sources and wheat)

• minecraft:village/plains/houses/plains_fisher_cottage_1 (the building with barrels)

Steps to Reproduce

1. Create a new world in the Superflat type, in the default Classic Flat.

2. Find a village, or enter the following command:

   1. /locate structure minecraft:village_plains

3. Find the aforesaid parts.

4. Find like 5-20 villages, repeating step 3.

5. Notice that these structures never occur in Classic Flat.

6. Now, create a new world in the Single Biome type, in the Plains biome.

7. Repeat steps 3-4 until you can find either structure.

8. Notice that these structures can occur in Single Biome.

Expected Result

The aforesaid structures should appear in Superflat.

Actual Result

The aforesaid structures do not appear in Superflat.