In the Bible Seth was the son that replaced Abel. Not that Stephen II could ever be replaced or I wanted him to be, I wanted Seth to have the full and healthy life Stephen was denied through an accident of birth.
In addition the bible said Seth was "Like his father in every way". There's a lot of truth in that statement.
Stephen Morse Quinney 1 and 2 and Seth Michael Quinney means we could share the SMQ monogrammed towels and save on laundry, so there was the practical consideration.