I played twice the halflings now and I strongly believe the flooding curse his way to heavy on them. I had a very (very!) late message about rebuilding a earth node.
By the time I had the message, able to rush a settlers (only 2 turns), sent it underground and rebuilt that node, half my land was flooded, almost all my crops gone, many gold structures razed and more important my main army (in a watchtower !) drowned leaving no defence at all in my land.
I could be wrong, but if so, anyone, please help me to know how to play them. But still, I think a player shouldn't have to know a "path" in order to play a scenario.
Don't misread me, I like this map, it's beautiful and enjoyable, but I think a work is needed regarding the halflings to have that map balanced.
My 2 cents.