Here's a great example I found when I was visiting.
Michael Dzuba married Maria Tarkulich who then became Maria Dzuba.
Peter Tarkulich, married Maria Dzuba who then became Maria Tarkulich
On top of that, it was customary to name the firstborn male after the father, secondborn after father's father and thirdborn after mother's father.
So it was quite ordinary for the son, father, grandfather and greatgrandfather to all have the same name.
To make matters worse, the women had customary name such as Maria, Helen, Anna, Suzanne. This went on for at least two centuries that I know of in Eastern Slovakia.
Suffixes were not used. Neither were middle names.
So you cannot make assumptions when examining the church books. An alias is often a fancy name for a nickname. My nickname is "Bill", but in the record books, it's always "William". My mother insisted I use my middle name in documents to not be confused with my uncle of the same name.