I've shot all of those divers over puddler decoys on occasion, but there is no doubt that they decoy better to their own kind. Goldeneye are definitely looking for other goldeneye and to consistently decoy them, goldeneye decoys make a lot of difference. Last week we weren't sure if the GE were in yet, so only took 4 decoys to put upstream from our regular spread which consisted of wigeons and redheads. That was enough to decoy a dozen groups of GE, so you don't really have to flood the spot with species specific decoys, but divers do like to see themselves. We have a dramatic increase in bufflehead coming in when we have a hen heavy buffie spread. I like to have 3-4 drakes and 7-9 hens when I target buffies.
I do a lot higher ratios with hen decoys and dirty drakes (immature drakes) when hunting divers. Since Divers take so long to mature you have a lot higher numbers of hens and immatures in a group of live birds and having decoy spreads that reflect that relaxes the birds a lot more in our neck of the woods. This is the first year I've tried a redhead spread and it's already brought in more redheads than we have ever decoyed in the past, it consists of 8 decoys, three of them mature drakes, two dirty drakes and 3 hens. Where decoying redheads in the past has been a very inconsistent deal, we had more redheads in the decoys last week than we have ever had in the past. The more I use a hen heavy spread for divers the more I like it.
It's hard to get hen diver decoys from manufacturers in ratios that I like to use, so I'm always converting drakes to hens.
It's not a tough thing to get swing passes from divers that put them within 40 yards, but we like them in the decoys for higher percentage shots with hard headed divers. We don't have a boat to chase down cripples nor do I like chasing my dog down river 300 yards on every cripple, so getting the birds close and dead is a must. Our decoys were set out 15 yards last week and nearly all the birds we shot fell within a couple of yards of the outside edge and several in the decoys. Not very many guys around here actually decoy divers, most are pass shooting off of islands and corner points on the river, but we like the birds over the decoys, feet in our face. A mixed diver pack of decoys is a great idea, but I'm sure most of those are drake heavy. It will improve the odds for sure, but make sure that you try to simulate what you see on your stretch of water.