Mob spawners in caves

With the new cave generation, there will be much larger caves. This brings the obvious problem of lighting it up so mobs don't spawn, which would be nearly impossible to do early game. Blocking off other parts of the cave is also no longer an option.

Most solutions to this that I've seen seem to involve changing or improving lighting, but I have a different idea. I think mobs should spawn much less in caves. I also think the mobs that do spawn should be different and more limited. Maybe endermen and zombies don't spawn in caves much, and skeletons and spiders spawn a lot more. Then, because there would be much less mobs, caves could be sprinkled with Mob Spawners. Then, part of the clearing-out process of caves would involve torching or destroying all these Spawners, and then the cave can be defeated (mostly) without having to light it all up.

I am not sure how these changes to mob spawning would work with the surface without making the game far too easy. Perhaps Undead mobs could spawn only on the surface (where villagers live, so it makes sense) and cave mobs could be the only things that spawn naturally underground, and add zombies and skeletons to the underground through spawners?

All of this should obviously vary by biome and cave biome.