I'm not quite sure if I understand your question.
According to the marriage it took place in Marlow. The category for Marlow, Mecklenburg-Vorpommern allready exists, and I linked it to the profile.
Where does the Sagard come from? I see no clue in the profile.
Btw: Be aware that we only use the modern regional structure as basis for the catagorisation. This way we can avoid the problems caused by the constant change of territories and the shifting of borders throughout the very complicated German history.
This would be the guidelines.