Forgive me if I'm misunderstanding what you are trying to do - but I think you
may be overcomplicating things.

I would stick to just three columns: name position  and year. You can then filter
either by name or position, sort by year  to get jobs into order. I realise that
you will be duplicating the name field, but the spreadsheet will be much easier
to deal with than one that covers 200 columns!