Is this a puzzle? Are we supposed to "devine" what the "rules" are? The output seems to have matching keys with two records in file1 and two records in file2 (2222, 4444). That's not much to go on for establishing the complete set of rules. What about matching keys with one record in file1 and one record in file2, with two records in file1 and one record in file2, etc.
YOU need to show an example of input and output with all the possibilities of interest. YOU need to explain the "rules" you want to use to get from input to output. Also, give the RECFM and LRECL of the input file. And which SORT product are you using?