[jwallstone]

Yes, Ishara's whip and the Poison Dagger are essential to high damage output with sprites and lake fairies. Since they do 1-2 or 1-3 damage, if you add +2 to that, you are almost tripling their damage with these items.

I do have to disagree about Sprites being better than Lake Fairies. Not always. They do have a slightly better damage range (1-3 vs 1-2), but with higher leadership (8 vs 7), you can recruit fewer of them, so this evens it out partially. Furthermore, the Whip and the Dagger have a MUCH greater effect on Lake Fairies because you can hire more of them. The power of these items essentially are proportional to the number of units in the stack. So I've found that if you are using these two items, go with the Lake Fairies, otherwise, Sprites are better for damage. I've actually tested this out with full stacks of both in my army. Just hovering over enemy units, the Lake Fairies had higher damage ranges (both the minimum and maximum were higher) than the Sprites.

Finally, since Sprites have Fire Weakness, they drop like flies fighting Dragons of other fire-based units, which pretty much are in all the hardest fights. Lake Fairies don't, so live much longer.