I have had a few decent spreads that mixed puddle and diver ducks. But for the most part, where puddle ducks congregate, you will often not see divers (save a few exceptions like Hollywoods and Jacks). At least thats how my waterfowling has been.

The places I have successfully used both have usually been the mouths of creeks, where they enter a larger river. Divers out in the open more, with the dippers back behind in a pocket slough or something similar. Wind has to be perfect, and more often than not, I have just had success with one kind or the other. Personal opinion, I'd pick what I wanted to go after, and save yourself some work and worry. The more decoys I put out, the more I have to tend to them. The dog goes through them with reckless abandon, the tide moves them, ice sticks to them, and sticks and other floatsom threaten to carry them off.

Just me saving me from myself.