1. Are you sure no earlier records exist?
Are there earlier records in the county that have not been microfilmed?
If not, then figure out WHY there are no early probate records.
Did the courthouse burn?
Was the county created from another county? Were other counties created from it?
Check the surrounding counties (history).

2. See if other records exist for this county or this family. What about the will books? Perhaps they have what you need?

3. Are these THREE men related? If so, then ONE of them living 'next to' your ancestors could just mean that he is living on (part of) family property. More information is needed.

Check for Family Information online.