There are so many things that can make two people, who appear to be the same, different. I have four generations of John George and many generations of William. Each of these groups of people have the same last name. I know of one situation where people have worked for years to separate two James whose last name and birth dates were the same.
While computer programs have been written to find possible matches, they are nothing but a flow diagram of rules. They will NEVER be able to replace the personal input to make decisions like the one you are requesting.
The only way to make these matches are to analyse every new person you add to your tree. Genealogy progresses with research not by merging trees.