Yeah I found disaster management the most exciting part, I never had to retry a stage until the last few stages (though I did get fucked up a number of times, I wasn't gong for the < 5 villages cheev), also if your going for full tree coverage wait till right at the end of a stage, or you can just finish the stage and it autosaves so you can pick up at the end and finish off if you need to later.
The Raging Earth stage ruined my shit, wish I saved during that. I retried that about 5 times, 2 of those times I reset because the ooga boogas insisted on traversing a sheer cliff and wouldn't change course no matter how many times lava kept killing them. Going back for my second attempt now and the < 5 villages destroyed achievement, already 1 village down on High Tides, don't know if resetting a stage resets how many villages you lost on it too though