Hi Ken,
Speaking generally Ordinal numbers are generally assigned by “historians” after the event to try and keep track of numerous individuals using a small pool of names.
The problem with this is that it’s arbitrary, if I only know of two Johns I’ll record them as I and II but if another researcher finds an earlier John what are they to do? Call him I and change the others to II and III but not you have two datasets with conflicting values.
The end result is that Ordinal numbers are next to meaningless, unless they were used by the person themselves during their lifetime.
Formatting is irrelevant 2 or 2nd or II or Jnr