The problem is, if there are any differences, someone has to then decide which to keep and which to discard.
You should make the appropriate changes before proposing the merge, that way, there will be no question that the two profiles represent the same person.
I have a couple of proposed merges where everything matches except their birth location -- one says Kentucky, the other says Virgina (of course, depending on the year, these could actually be the same). I have to do more research to know which to keep and which to discard, and why.
Present your research so that the ones completing the merge can verify your decisions.