Hmm. This might be a mere coincidence, or...
In my husband's line, there is a Mares wife, born mid 1700s, likewise a Mach. And I'm working with a friend who has Machs from the same region. All southern Moravia. I am not working on extending the research on the brothers and sisters, so I haven't run into these names in your time period.
Are you from Nebraska? If so, what county? Have you located any ancestors in the Sobotka book? If you are unfamiliar with this resource, I'd be glad to help.
Mary Sramek Levesquemary@levesque.com