[Experimental] Swamp biome now mostly generates as microbiomes

When generating worlds behind Caves & Cliffs experimental toggle, most of the swamps now generate more like microbiome as opposed to a big one biome.

Step to Reproduce
1. Create a new world with caves & cliffs experimental toggle on.
2. Find any swamps

Expected Results
Most swamps generating aren't microbiome

Observed Results
Most swamps generating are microbiome, even to the point it only generating with different colored water and some lily pads as their entire biome.