Sweetlychee, not sure if you are aware of this or not, but corgis ARE dwarf breeds. There are several achondroplastic breeds and it can occur in any breed. On the Corgi Rescue list we've seen dwarf Rotties and Golden Retrievers labeled as corgi mixes.
Miniature Maltese?
Now how much smaller than 4 to 6 pounds does someone need a dog to be?
Debbie