First build should be a scout. It's done 3 turns sooner, and moves faster (ignoring terrain, including those stupid river crossings). So it will net you about one more hut on average. Totally worth it. Plus you get to start on your second build 3 turns earlier. After that, though, I don't think I'd build any more. I tried scout-scout once when I had land in three directions and it seemed the AIs were all far away. Even in that situation it may or may not have been worth it. I didn't like delaying the worker that long. I think scout-worker-warrior will often be correct.