Numbers can be misunderstood; the ALBCruns surveys and contacts sources to TRY to have accurate numbers. THis isn't an easy task IMO.
THe important thing is to understand that BBW rules the commercial world and very few people provide their own table birds; from what I have read, the BBB is the next in number, but far, far fewer than the BBW. THere are a few other commercial varieties that are not very popular now as well.
Over the last 10 years the numbers of breeding pairs of the "heritage" turkeys has been increasing according to the ALBC numbers. More people have taken an interest in raising and keeping the old breeds. There are newer varieties available now as breeders have persued an interest in developing more turkey breeds. Only a few are APA recognized; those are the primary ones ALBC surveys for.
When you compare the number of birds the BBW/BBB versus all other turkeys, the population of "other turkeys" is almost nil. This is what, IMO, the ALBC is trying to convey and that more people are needed to have turkeys. FRom people who breed them, to those that want a pet or want a nice Sunday dinner.
If you are interested in breeding other than BBW/BBB, go for it. There are many to choose from! Like Midget Whites.
As for hatchery birds, they have a practical purpose; I woudn't have such an interest in poultry now if I hadn't started with "hatchery" birds. THey are a resource; and just because someone has only a few birds, doesn't make the flock better than a hatchery bird unless better selection has been applied. Becoming a good breeder of birds takes a lot of knowlegde and practice IMHO. Work with what you can find . . . .learn as you go.
Enjoy the Midget whites and good luck. I tried to copy the web address for the midget whites at ALBC. THere are other resources too. I looked into them but didn't think I could find stock. I will look into them again.
http://www.albc-usa.org/cpl/midgetwhite.html