Good luck on your new map. I'm playing exclusively in Survival mode on a map that is 98% water and had only two trees on the entire seed. My world has grown quite large, but not a single user-placed block is above water--everything is submurged. I hope
to destroy the few mushroom islands that exist so that EVERY block (not just every building) is below the water line.
To answer your question, YES it is possible to spawn villagers, but not the way you are going about it. You have to spawn zombie villagers first and then cure them to make them villagers. Zombie Villagers comprise 5% of all spawned Zombies. They generally
behave as ordinary Zombies, but their character model's head and face looks like that of a villager, especially the nose. Of course, you have to be playing in at least Easy Mode for them to spawn (since zombies don't spawn on Peaceful). Keep in mind that,
as of TU15, Zombie Villagers do NOT spawn from Zombie spawners--they only spawn from dark places (they used to in TU14, but no longer). One way to go about spawning Zombie Villagers is to dig a huge spawning area under ground and keep killing Mobs until you
get a Zombie Villager. This will take a while. As you know, only some of the Mobs spawning will be Zombies and, of the Zombies, only 5% will be Zombie Villagers. Once you get a Zombie Villager to spawn, you need to segregate the Zombie Villager from the
other Mobs and cure him.
Zombie Villagers can be cured by throwing a Splash Potion of Weakness at them, then feeding them a Golden Apple. A loud hissing sound will be heard if successful, and the Zombie Villager will begin to shudder. The transformation will take 2–5 minutes, during
which time the Zombie Villager will still attack and must be shielded from other attacks (and sun damage if you are doing this above ground). While the zombie is being cured, it will have the Strength I effect in normal difficulty, or Strength II in hard difficulty,
making it more important to isolate the zombie. As I said, during the curing process, keep the Zombie Villager away from any other zombies, because the other zombies will stop the curing process. Conversion can be sped up by around 4% by surrounding the
zombie villager with a 9x9x9 of beds or iron bars (or combined).
And at the end of this process, you have a villager. Move him to a place with hours and doors and he'll be happy. Since you are playing a water map, I should also note that if you build the village underwater you will not be able to breed villagers (since
villagers only breed if they have direct access to the sky). I am presently building a large underwater village in my world. While I can't breed the villagers in the underwater village, I can populate the village by continuing to fine and cure Zombie Villagers.
I hope this helps.
