[Turin]

Well you get lots of free picks due to +3 cold preference, your mages are the cheapest AND the best(for combat at least) of all nations. You will get the airqueens(best SCs), if you don´t make serious mistakes.
You can expand pretty well early on with blizzard warriors and mammoths and you SC pretender.
Other nations have a very hard time attacking you, because of the fatigue effect from cold3 and your fantastic mobility. Once you have evocation 6, you can destroy entire armies with a seraph + high seraph hit squad(seraph wielding staff of storms and ring of tamed lightning, set to retreat, high seraph casting wrathful skies/mirror image etc). Even better you can teleport that very cheap hit squad(cost 275 gold and 30 air gems) around with cloud trapeze.
Another advantage is that you can build clams as soon as you get construction2.
But mostly the cheap superior mages make caelum the top nation.