I agree..
I agree with the post above, the game is about counter-attacking, like this....
Ranged over Air
Melee over Ranged
Air over Melee
Of course, different creatures are more powerfull than others depending on the race, of course, if one is weaker than the other, then somewheres else in the race you are compensated by the loss, so if your 3 archers get taken out by a Wyvern, your Dryads probably make up for the suckiness of the archers.
I personally favor the Elves, but have had some success with Orcs as well.