over here in Limburg they went by their first or their middle or their third name! It was, and still is, very common to have three baptize names, for example my baptize names: Catharina Andrea Johanna; Catharina after my father's mother, Andrea after my mother's father and Johanna after my father and mother (Johannes and Anna) and I am called Irma. Can you still follow it? I should have been called after my grandmother Catharina but they called her "Tring" and my mother didn't like that and choose Irma, only my father forgot to give up that name at the city clerk so officially I have 'only' three names.
But the names Johannes/Joannes and Maria were used very often. Also the village church patron was mostly used in the names. and because of that many people would have been called Jan (after Johannes/Joannes) or Maria and that's why one is called by their first, thee other by their second and again others by their third name.
Sounds a bit complicated but it's not after you finally know your way around :)
And because I am living in Limburg I am very much interested in the family names you are researching over here. Take a look at my home page www.limburgemigrant.nl