Software :: Create A Genealogy Graph From A Excel Spreadsheet?

in order to visualize the mentor-student relations inside my fraternity, I'd like to create a genealogy graph from a Excel spreadsheet. This works way better than expected, but there is one final issue. To demonstrate, this is a smaller version of the graph:

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It is ordered by year , while members are placed in the appropriate timeslot and are connected to show said relations. Unfortunately, as you can see, during a few years when the choosing of mentors was partly suspended due to historical reasons (WWII etc.), the members stack up to the right of the graph, widening it a lot. Is there a way to specify that they are supposed to be distributed among the members that are part of the structure in order to achieve minimum width?