For the roundabout, you should end up with five warriors and something like 8-10 mages. Two of your warriors take the place of the stone jutting out by each entrance to the roundabout, one takes the middle spot, and the other two take the spot inbetween the entrance and exit paths, right by them. Upgrade elements, but don't worry about going beyond that until all units are in place. Remember, you'll want to clear out stones for 2-3 mages by each entrance to the roundabout, strategically placed.
to GTUK: The roundabout is tricky. I don't remember my exact strategy, but I put a warrior in the middle square and mages everywhere else *except the two squares nearest the entrance and exit (where I put a warrior in after I survived the first one or two rounds of flying), and I left the two squares next to each other by the exits alone (I think I put one mage in there, but he never did anything.) Finally, I cleared out some stones and put in probably another two or three mages and a warrior each by each entryway into the middle ring. The warrior took the spot jutting out. Finally, make the warrior in the middle lightning asap. All mages are fire, and the rest of the warriors you will have to decide.
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