Can I replace the father of 5 children at one time?
He is shown as the father of 4 sons and one daughter, however he is the father in law not the father of the sons and the grandfather of the 'daughter'.
Given that the needed change is different for one of the relationships than the others, no, I don't think there's a way to do it all at once.
And now that I think about it, I don't think making a father into the father-in-law of four sons (really?) is possible in one step, either. There's a trick for attaching a parent to multiple children at once using a merge, but that depends on the children already being correctly attached to the other parent.
I think I fixed it, no spouse was listed for the supposed father. The last name for the sons was not the name of the supposed father.
I added a second parent with the correct last name, there was an existing profile that made sense, though it might not be correct, and removed the definitely incorrect parent.
Some of the profiles have been merged multiple times.
I'll continue to look for other ways of verification.