My favorite strategy is to use Peter Elf Face or whatever his name was and just build the stables then upgrade the horsemen all the way. Hermes Speed is ridiculously effective and when using that strategy I don't really have to build any other units, though Golems pulverize everything instantly while under the effects of Hermes Speed and that came in handy in the last level.
 "Kill the Plumber"){kind=icon}
 "Nano Kingdoms"){kind=icon}