Adding 2 water pans?

Using an offset smoker. Next cook: Brisket.







So I always place my water pan under the cooking grate, next to the firebox usually under the food. (oily/fatty water pan = more difficult for water to evaporate...)





but now, after reading and thinking, I might try the water pan on top of the cooking grate. smaller pan (around 3in x 8-10in)





So can i use 2? one small on top, and regular sized on the bottom. or  is it too much? irrelevant? I'll be keeping a close eye on the smokers temp.