More Overworld Biome Variants

My Idea:

Essentially, add extra variants to existing biomes. No new blocks would need to be implemented, unless new features are added if included with a bigger update. There are so many ideas that could work, but to comply with guidelines I will provide a single example to give a sense of what I am thinking of.

Desert Shrubland - A sub-biome of Savannas that generates intermittently along borders with deserts or badlands. Has oak shrubs scattered throughout, and occasional patches of sand or red sand. Same spawn rules as Savanna, with the exception of passive mobs that would not make sense in a semi-arid environment. Husks can occasionally spawn, but normal zombies would still be 50% of the zombie spawn count.

To conclude, adding more variance to the Overworld could make exploration a bit more fun by (1)  making certain transitions smoother and (2) adding variation to large biomes.