Even though an F/O (co-pilot) may have a piece of paper saying he is qualified on the type all airlines I have worked for carry a third pilot for safety reasons until the new F/O is cleared to operate without a safety pilot.
Which is the same in Germany. Usually for two or three days on the line until an incapacitation check flight has been done. It is the same for a new captain and for any pilot after he did a new typerating. In the case of experienced pilots within the company the time with a safety FO may be shortened to one day though.
From what i have read the 630 hours are probably the time on type, which would fit with his time since he started the typerating in 2013.