I feel a mix of sizes works well

I would use part Hot buys and oversized
I run Hot buy mallards , oversized mallards , oversized blacks , Pintails and Green wing teal
May add 1/2 doz of Gadwall and 1/2 Doz of ringneck decoys this year

For walk in hunting
I convertedall the standard sized and Oversized decoys to water Keel by cutting a small hole in each end of the keel and dumping out the sand

As I use a Deer cart to haul in my gear , I haul in 4 - 6 doz decoys , a mojo , waders and blind bag on the cart

John